Chex Quest

You're stranded on hell Bazoik going out of your way to discharge buckshot zorch to the hellspawn Flemoids eventually saving your comrades from a baron of hell Flemoid.

The Ultimate Doom
While Chex Quest is normally played up to E1M5 (5 levels), it actually shipped with the rest of the levels from The Ultimate Doom dummied out, complete with broken and placeholder texturing. Suffice to say, this made sharing the game highly legally difficult.

Fortunately, the much-belated release of Chex Quest 3 excises these id Software creative works from the IWAD, thus finally giving it a clearer legal status.

Unused Player Sprites
Multiplayer functionality was stripped from the setup program. Consequently, the player sprites are not seen in-game, leaving it unused in the shipped game.