SNES Doom features 22 levels from the PC version, but the player's heads-up display does not take up the whole screen. The floors and ceilings are also not texture mapped. The game lacks a back-up system, meaning that each episode must be finished from the beginning. Multiplayer was available if the player bought an XBAND modem. Due to memory limitations, the enemies are only animated from the front, which meant that they always appear to face the player. This renders monster infighting impossible, although it was made possible for monsters of the same type to damage each other with projectiles in this version of the game. Perhaps as a concession to this limitation, circle-strafing was also removed, though standard strafing is still possible. Also, perhaps as a means to conserve processing