Faceball 2000 (フェイスボール2000) is a first-person shooter originally developed by Xanth Software F/X for the Atari ST under the title Midi Maze. The Game Gear version was published by Riverhill Soft and was only released in Japan. Faceball 2000 also came out for SNES, Game Boy and Turbografx CD/ PC-Engine CD. A port to the Virtual Boy was in development, but got cancelled.

You control a H.A.P.P.Y.F.A.C.E., which stands for Holographically Assisted Physical Pattern Yielded For Active Computerized Embarkation, and you need to find the exit in each level within a time limit. Similar to Wolfenstein 3-D, levels are plain and based on a rectangular grid. You can turn around, shoot, and walk back and forth. Enemies consist of other H.A.P.P.Y.F.A.C.E.s. You have a single weapon which can also release one shot at a time, but has infinite ammo. You can find capsules which contain items or hints. Items include extra-lives, keys (open secret doors), band-aids (restore health) or coins (give points). You score points along the way, and you get an extra-life for every 1000 points. The game has an automap which you can look at any time. There are switches which remove walls or lock and unlock doors. You can take a certain number of hits before you loose a life. You can find armour which will take a number of hits before you get injured. Apart from using band-aids, you will also heal over time if you don't get hit. The game has no passwords or save feature. Instead, the level of difficulty select the level you start at. The lowest level of difficulty starts at level 1, the highest at level 51 (out of 75).
Apart from the single-player levels, the game also has an arena mode for two players.