TI Invaders is a clone of the original Space Invaders. Players choose from 2 difficulty settings: "Merely Aggressive", where the enemies fire sporadically and rarely target the player; and "Downright Nasty", where the enemies constantly target the player with their shots but the enemies' point values are doubled.
After each round is a Bonus Round where the player shoots a UFO, which will then change direction. Shooting it again will make it change direction again, and so on. After each hit, the UFO speeds up.
Source: User Summary
