Proton

Proton is a sort of simple Lazer Tag type game where two teams of combatants shoot at each other trying to score points. The game works on a grid-based system which isn't the best model for this type of game. It's difficult to see where your opponents are, since only a small area of the map is shown. Whenever you get hit, your gun freezes and you can't shoot at anyone for a few seconds. Also after you register 5 hits, you must "clear" your gun by shooting the opponent's base. Overall it's an interesting game distributed for free in 1987 but the gameplay (as well as lack of a two player mode!) isn't very compelling.