That's assuming you can get your hands on DOS versions of the game. The supposedly Windows-compatible versions have given me all sorts of problems.
- UFO Defense and Terror from the Deep were DOS-only, easily playable with DOSBox or VDMSound.
- Apocalypse was released as DOS and W95 version. The DOS version ... see DOSBox. The W95 version ... a little tricky, but playable.
- Enforcer is based on the Unreal_1-Engine. Should be playable without problems
- Interceptor is some bugridden crap. This should NOT BE SOLD on Steam. As a freebie, when you buy all games, ok. But not sold for even a penny!