Difference between revisions of "Bugs: NES"

Revision as of 11:57, 10 June 2008

The following is a list of all known programming errors and technical issues with the NES version.

Arm Collision Detection

If you swing on your arm just below where a soldier is walking collision detection will occur between your arm and the soldier even when they're not touching. This happens because the collision mask used on the arm is taller than the arm actually is.

Type: Programming oversight
Versions: All

Back From the Dead

If you die, and upon your falling death land on a bullet canister, which also happens to give you a hit point you will go up to full life instead of dieing and you won't lose a life. This error occurs because collision detection isn't turned off when you're dead, so you can still pickup bullets. Also, you don't actually lose a life until the screen goes black.

Type: Programming error
Versions: ?

Broken Arm

By using the Walk In Barrel bug, it's possible to sever your bionic arm. First, get stuck in a barrel. Then throw your arm to a nearby ledge. Press left or right and the game will force Rad out of the barrel, but it will keep the arm connection, thus severing the arm. This occurs because the forced movement of Rad doesn't cause his arm to lose grip although it should.

Type: Programming error
Versions: All

Disappearing Death

When a construction soldier dies he simply disappears. This is because there are no death animation graphics for them and because the default soldier death used for most soldiers would look unusual considering their size. Since the enemy is only used once late in the game it is assumed that their missing death animation was the result of a release deadline.

Type: Design Oversight
Versions: ?

Enemies Don't Disappear

Normally, when you destroy the main system at the end of each area the game freezes you for a nice dramatic effect and any remaining enemies in the room disappear. Unfortunately, the game does not always clear out the enemies! So, it's quite possible to destroy the main system, and then take a bullet in the head because you can't duck anymore.

Type: Programming error
Versions: ?

Enemies Walk On Spikes

Only Rad has collision detection for spikes and springs which means that even though they should be affected by them, enemy soldiers are not.

Type: Programming oversight
Versions: All

Fall Back

When you press down on a swing it disconnects the bionic arm and drops Rad with the momentum that he has from swinging on the bionic arm. However, if you're falling, and just as you connect your arm, you press down to drop again, sometimes you will fall in the opposite direction that you should fall.

Type: Programming oversight
Versions: All

Flare Bullet

The game treats the flare bomb as a bullet. Its flag, location, and velocity are all stored in the same memory that is reserved for a player's bullets. Not only does this mean that firing a weapon with three bullets will make the flare immediately disappear, but also the flare has collision detection with enemies. However, a flare doesn't have a damage flag, so if you walk under an enemy and shoot a flare, you will cause an error in the game and reset the area.

Type: Programming error
Versions: North American, European

Flare Offset

If you are ducking when using the flare bomb the flare won't shoot from your body, but from your gun.

Type: Programing oversight
Versions: All

Friendly Fire

At the end of a meet with enemy sequence an allied soldier is waiting in front of the helicopter waving you on in. Even though he is an ally if you touch him you take damage. This bug exists because no special code was written for non-hostile sprites in the combat sequence. Everything that isn't Rad uses the code for an enemy.

Type: Programming error
Version: Japanese

Glowing

If you time it just right, you can take a bullet just as you kill the last soldier in a meet with enemy sequence. If you do this you'll start flashing invincible. But just then you begin automatically walking to the helicopter. Normally, your invincibility would wear off, but when you're automatically walking the invincibility counter doesn't count down and you remain invincible until you enter the helicopter. This bug is not possible in the Japanese version because your ally soldier enters the helicopter first which takes long enough for the invincibility to wear off.

Type: Programming oversight
Versions: North American and European

Hovering

Due to the way the Rad's sprite changes when he throws his bionic arm out, it's possible to make him look like he's hovering in mid air. This is an issue with how collision detection works with the player's sprite and the background.

Type: Design oversight
Versions: All

Kick a Ball Into the Floor

If you swing up into a moving ball and there is a floor in the way, the ball will be forced into the floor. It will continue to spin and you can still get hit by it, but it won't be able to move anymore.

Type: Programming oversight
Versions: ?

Killed Twice

In area 4, if you knock a knife wielding soldier into an area with spikes, and then move him off screen, it's possible to die on the spikes and fall forward so the knife wielding soldier comes onto the screen. Seeing the player, the knife wielding solder will attack and stab your dead body, making your body fly into the air a second time. You still only lose one life.

Type: Programming error
Versions: ?

Knocked Into the Wall

At the end of area 12, if you get caught in the giant soldier's wires he can knock you into a wall and you continue to fall until you make it all the way to the beginning or the map. This happens because the recoil that you get when you hit the giant soldier occurs without wall detection.

Type: Programming error
Versions: ?

Lazarus

If there is only one enemy soldier left on the screen and you both kill each other, the automatic movement sequence will kick in and you'll get up off the ground and walk into the helicopter, even though you should be dead. This occurs because the automatic sequence doesn't check to see if you're dead, and you don't lose a life until the screen blacks out. This isn't possible in the Japanese version because as your ally walks into the helicopter he gives the program enough time to make sure you're dead.

Type: Programming error
Versions: North American, European

Manual Inconsistencies

These are all of the sections of the manual that don't match up to the game.

• Cover: Uses artwork from the arcade game. There are no mechs or giant bats in the NES version.
• Page 4: Same arcade artwork. Refers to the Badds as the NAZZ.
• Page 5: The shoot and bionic arm buttons reversed.
• Page 6: Refers to the wide cannon as the wide gun and the rocket launcher as the rocket gun.
• Page 10: The weapons are in the wrong order in the weapon selection screen.
• Page 13: Refers to the wide cannon as the wide gun and the rocket launcher as the rocket gun. Joe's Machinegun doesn't fire at 22.5 degrees.
• Page 14: Claims player shoots in 8 directions, but it's actually 12 direction.
• Page 15: Refers to the energy recovery pills as medicine, the rapid fire device as the magazine system, and the pendant as the charm.
• Page 17: The suicide bomber is drawn top-down which doesn't occur in the game.
• Page 18: Has a picture of the wired gunner boss, which doesn't exist in the game.

Map Mistake

The lamp post at the start of the difficult swinging session in area 6 goes right up to to top of the screen. Normally a map is surrounded by walls to prevent the player from leaving the map. However, in order to make pits kill you the programmers wrote code to kill you if you ever leave the map. Since the lamp post is not a wall you can climb on top of it, but doing this will put you off of the map. And what happens when you leave the map? You die!

Type: Design oversight
Versions: All

Message Too Early

Because the barrier in area 15 disappears with any gunshot in the North American and European versions, it's possible to get the delta communicator and the message about Super Joe long before you're supposed to hear it.

Type: Design oversight
Versions: North American, European

Mine Cart Hovering

If you die in area 9 and your body falls unto a mine cart, the mine cart will continue moving with you on top of it. Eventually the mine cart will fall or hit a wall, and explode. Your body will end up hovering in the air because gravity no longer applies after you hit the ground after being killed.

Type: Programming error
Versions: ?

No Friendly Fire

All enemies are completely impervious to other enemy weapons. Bullets, lasers, explosions, etc. that come from enemies do not harm any other enemies. This is probably a combination between game design and technical limitations. It would take too much processing power to handle collision detection for every sprite, and it would also make the game a lot easier if enemies killed each other for you.

Type: Technical limitation
Versions: All

Pass Through Rocks

If you get right up close to a rock wall, turn away from it, throw your arm directly up, pull yourself up, and then turn towards the rock wall you'll be teleported to the other side of the wall, and your bionic arm will be severed.

Type: Programming error
Versions: Japanese

Parachute Into Barrels

When paratroopers fall from the sky they will land on the first platform they collide with. However, they will not land on barrels which create the awkward appearance of seeing a paratrooper stuck inside a barrel.

Type: Programming oversight
Versions: All

Permanent Invincibility

If you die, and as you're falling land on medicine, you won't die or lose a life. Instead, you'll gain back all your hit points and become invincible permanently as long as you don't leave the map. This occurs because when you die the "player dead flag" gets flipped on, but the medicine brings you back to life, but it doesn't flip the "player dead flag" off. When the player is dead enemy collisions don't occur, but you can still pick up bullets.

Type: Programming error
Versions: ?

Permanent Palette Shift

If you take damage, and while you're flashing invincible swing into and hit a rock wall your invincibility wears off instantly, but your colors remain palette shifted until you leave the map.

Type: Programming error
Versions: Japanese

Rock Display Glitch

Rock walls don't always get drawn properly when they're refreshed while the screen is moving vertically. Sometimes you'll only see two rocks when all three are supposed to be there.

Type: Programming error
Versions: Japanese

Sprite Mirroring

In order to save space many early videogames mirror their sprite graphics to depict a change in direction. This creates issues for human sprites because they're constantly switching their dominant hand when they're seen holding something. For example, Rad's bionic arm and gun swap hands each time he changes direction. The same is true for all enemy and allied soldiers that hold weapons.

Type: Technical limitation
Versions: All

Standing On Spikes

With the proper timing it's possible to create a situation that's physically impossible. If you throw an angled arm just in time to save you from hitting spikes it's possible to not take any damage from them, but still be walking on them. This is a bug in the order of collision detection. Once the arm successfully grabs, no more checks are made to see if you're standing on spikes.

Type: Programming oversight
Versions: All

Standing On Springs

For the same reason you can stand on spikes, it's possible to stand on springs that would normally bounce you up.

Type: Programming oversight
Versions: All

Survive a Missed Bazooka Shot

There are three known ways to avoid being immediately killed when you miss the final bazooka shot.

1. If you fall and immediately duck the machine gun can't hit you.
2. If you fall really close to the edge of the wall the machine gun won't be on the screen so the bullets can't get you.
3. If you have more than three hit points and purposely hit the spikes on the way down, you'll be invincible long enough to hide under the machine gun so the bullets can't hit you.

Type: Programming oversight
Versions: ?

Swing and a Miss

Construction soldiers may be the Mike Tyson of the game with a punch as powerful as a bullet, but they suck for accuracy. If you duck below their punches they won't advance, but they will instead just keep punching the air until you move. This design flaw probably made it through testing because the enemy is only seen once and is easy to kill from a distance.

Type: Programming Oversight
Versions: All

Useless Barrier

The barrier in area 15 is meant to prevent you from learning information and getting an item until you have the 3-way. This was messed up in the North American and European versions, but even in the Japanese version it's possible to avoid the barrier all together by swinging under the ground. It's difficult to time the swings just right, but it's possible.

Type: Design oversight
Versions: All

Walk In Barrels

Unlike walls, barrels don't knock you back when you swing into them. This makes it possible to grab above a barrel, swing into it, and then press down to drop inside of it.

Type: Programming oversight
Versions: All

Which Hand

During the ending sequence as Rad and Super Joe flee the base while attached to the helicopter, Rad's bionic arm is seen on his left hand. When they are seen in close up his bionic arm is his right arm. This isn't a case of sprite mirroring, this is an actual artistic mistake.

Type: Design oversight
Versions: All

Wired Boss Position Error

When escaping area 12, it's possible to get grabbed by the wired boss's wires and have Rad's Y position on the map get thrown off. When you climb out of the hole you'll exit a platform earlier than you should.

Type: Programming error
Versions: ?

Wrong Recoil Palette

When an enemy soldier is hit by the bionic arm he recoils back. The same graphic is used when a solider is killed, but they flash when they're killed. In order to save space, the game only has one recoil graphic for all soldiers that recoil, and they all have to share the same palette. This means that if there are multiple colors of enemy soldiers on the screen, only one will be properly colored. If you knock them back, they will recoil to a different color uniform, and then when they stand up again it will be the correct color. This can be seen on the parabombers of area 8 and the knife wielding soldier in area 19.

Type: Programming oversight
Versions: ?