Match 3 Tower Defense Game
Matches create towers to defend against aliens. If 4 aliens get through, you lose.
Match 3 waters to make a water gun. It shoots left/right only. Match 3 microphones to make a speaker. It shoots in all directions but has short range. Match 3 targets to make a bow. It shoots up/down. Match 3 gems to get an extra swap. Match 4 of anything to get an extra swap. Match 3 of a tower to get an upgraded tower that shoots faster.
When you run out of swaps, night falls and aliens invade.