In Crash Twinsanity, there were originally Cortex minigames. These, most likely, would have parodied Pac-Man and Space Invaders. It is unknown how the player would access these minigames. There are only two known minigames, and as mentioned before, they parody Pac-Man and Space Invaders, both popular arcade games. The Space Invaders parody minigame might have used the same set up as Space Invaders, but with different adversaries and with Cortex instead of a spaceship. There's a chance that Cortex would use a UFO for a mini-game. Some information about this can be found here.