Doom II for Game Boy Advance

Doom II for the Game Boy Advance was developed by Torus Games of Australia and published by Activision. This version of the game does not run on a port of the original Doom engine, but instead runs on a custom engine shared with several other first-person shooter games called the. The differences between the GBA Doom I and Doom II, besides the maps, are:


 * All maps and monsters are present, including the Wolfenstein secret maps and Wolfenstein SS enemy. Also, all items are present, including the previously absent light amplification visor and the blur artifact.
 * The demon was given its original death sound.
 * Health potions and armor bonuses give only 1%.
 * The original PC status bar is used, just scaled for the lower resolution.

Since the original Doom engine was not used, all content and mechanics had to be converted over to the Southpaw Engine. In terms of content, the game is nearly identical to the PC version, with only very minor changes. However, converting the gameplay and rendering functions to the Southpaw Engine resulted in a number of visual and mechanical inconsistencies from the original game; some are mostly cosmetic, but many more can have a significant (and usually detrimental) effect on game functionality. Additional differences from the original Doom II not already mentioned include:


 * The super shotgun's shells are flesh coloured, just like the face's blood.
 * The super shotgun reloads faster; also, its sound effects are not synchronised with the animation, resulting in the animation playing longer than the sound effects.
 * The shotgun's behavior was changed so that it fires in a conical pattern instead of a fan pattern; though this behavior is more "realistic", it deviates from the original design of the weapon and affects its usage significantly, as "grazing" indirect hits or hits against multiple enemies are much more difficult due to the substantially lessened horizontal dispersal.
 * The chaingun no longer fires in bursts of 2; instead, it fires only 1 bullet at a time when used. It also has a noticeably higher rate of fire.
 * The pistol and chaingun no longer fire with perfect accuracy when single shots are fired; instead, the bullets are fired with the same deviation as though fired during a sustained burst. This makes "sniping" or chaingun tapping nearly impossible.
 * The chainsaw pushes enemies away from the player, instead of simply dragging the player into the enemy; this makes using the chainsaw risky and difficult, as the enemy can be pushed out of the chainsaw's area of effect, allowing the enemy a chance to counterattack.
 * The plasma gun no longer plays the "recoil" animation that normally plays after releasing the attack button; this makes consecutive usage of the weapon (such as single shots or short bursts) faster.
 * Dropped weapons and items give full ammo, instead of half.
 * The box of rockets gives ten rockets, not five.
 * A message is displayed on-screen when the player finds a secret area.
 * Doomguy's status bar face changes at different health values than in the original game (about 5 - 10 points lower health for each transition). While seemingly featuring a higher color depth than the predecessor, the blood on his face is now colored brownish.
 * The music tracks "Between Levels" (MAP04) and "Getting too tense" (MAP28) were dropped, most likely due to cart space. In their place was "Into Sandy's City" and "Evil Incarnate", the music to MAP09 and MAP31, respectively.
 * "I'm Too Young To Die" does not give double ammunition; it only reduces damage.
 * Like the original GBA Doom, "Ultra-Violence" was renamed to "Nightmare!"; true "Nightmare!" was removed.
 * The color palette used is not identical to the color palette used in the original Doom games, resulting in some objects or surfaces suffering from palettization issues, especially under certain lighting/colormap conditions (such as being under the influence of a Berserk Pack). Browns and tans seem most affected. The pain elemental displays this more noticeably than other examples; its body appears slightly splotchy even under "normal" lighting. The first "episode" skymap also illustrates this.
 * Monster blood is green instead of red, and most instances of extreme gore (such as gibbing) were removed. Additionally, if the player is damaged, a bullet puff is produced instead of a blood splatter. (This edition is rated "T" for Teen, whereas most editions received an "M" for Mature.)
 * Enemies are drawn slightly larger relative to the environment than in other versions of the game; however, their bounding boxes are not scaled to the same degree. This makes shots tend to "miss" when they should appear to hit, if the shot was aimed at the periphery of a monster's visual representation.
 * Vertical auto-aim is not reliable; the game will usually not aim for barrels on a lower altitude than the player, and hitscan shots fired at floating/flying enemies at close range will sometimes be fired above or through the monster instead of at the monster.
 * The player is now allowed to walk underneath flying enemies, or jump over the heads of monsters below. (This was possible in Doom engine games like Heretic and Hexen, but was not allowed in vanilla Doom.)
 * Monster corpses will obstruct the motion of a door, causing it to reverse its motion if it tries to close on a corpse (as opposed to crushing or destroying the corpse). Since monster corpses disappear after a few seconds, this is only a temporary issue.
 * Enemy AI will shut off at times, presumably to avoid slowdown due to heavy processing. The decision by the engine to shut off any given enemy's AI seems to be based upon a combination of distance and/or number of sectors between the monster and the player, and NOT based exclusively (if at all) on whether or not the player is within line of sight. Such a monster can sometimes even be shot and damaged by the player and remain "dormant" (an example is the Imps across the water in the first outdoor area in The Gantlet).
 * Player movement when strafing or backpedaling is much slower relative to other versions of Doom, making it more difficult to avoid projectile attacks or sudden ambushes.
 * The bounding box of the lost soul's attack is much larger than it should be, and causes the player to receive damage if the player is within several feet of the lost soul in any direction when it attacks (sometimes even if the player is behind cover or around a corner) and not just on a direct hit. Not only does this result in easier hits against the player, but it also makes using the chainsaw impractical, as the player will suffer damage from the lost soul's attack long before the chainsaw can make contact with the lost soul.
 * The former commando's chaingun produces the same gunshot noise as the player's, rather than using the shotgun's sound effect.
 * Revenant missiles do not smoke when homing, and are fired from the revenant's waist (~32 units high, like all other missiles). Non-homing missiles are rarely (if ever) fired.
 * The arch-vile's flaming sounds are missing and the explosion sound (DSBAREXP) is played when the attack is initiated. Also, the flames appear lower in the player's view, and damage dealt is dramatically lower.
 * The mancubus turns his body roughly 45 degrees from the player during his first and second attacks (instead of simply angling the path of his projectiles), which usually causes his projectiles to miss badly. His third attack is performed more-or-less correctly.
 * The BFG's tracer attack uses the BFG plasma balls explosion sprites and the explosion sound used for the BFG plasma balls impact is the standard explosion sound rather than its own.
 * Health items (such as medikits and stimpacks) are now erroneously counted towards the "Items" tally at the end of the map, making a score of 100% more difficult to achieve (since health items can only be obtained if the player is not at full health).
 * Enemies killed by traps or friendly fire from monster infighting are erroneously not counted towards the "kills" tally at the end of the map. Only monsters killed directly by the player appear to be counted.
 * Industrial Zone and The Chasm are split into two maps each to avoid slowdowns and memory constraints. However, the scoring on these maps was not adjusted to reflect the removal of the enemies, secrets, or items relocated to the corresponding "second" map, making a score of 100%/100%/100% on these levels impossible. (Whether the "removed" entities are still present in the map, or whether these maps have a special hard-coded scoring exception, is unclear.)
 * The Wolfenstein secret maps and Wolfenstein SS enemy are present, but all Nazi imagery and Hitler paintings have been replaced by iconography from Return to Castle Wolfenstein (presumably to maintain the game's "T" Rating by the ESRB).
 * Weapon damage dealt to other players during deathmatch is reduced by 75%, making deathmatches much more protracted than usual.
 * The armors system in this game is somewhat broken; armor only provides protection in the map it was collected in, even though the numerical value of the armor carries over from one map to another. If the player enters a map with any armor percentage above 0%, the game will ignore the player's armor value, causing the player to suffer full damage from attacks. This happens until an item which affects armor value is picked up (either armor, megaarmor, a megasphere, or an armor bonus will work); this will "reboot" the armor system to properly protect the player again. If such an item is unavailable (or if the player can't collect the item because their current armor value is higher than what the item offers), then the player is, for all intents and purposes, forced to play with no armor, even if the player's actual armor value indicates the player should be protected. This bug has also been confirmed by publisher Activision.
 * The damage mitigated by armor seems to be no more than 30%, regardless of which armor type the player has.