Stealthy fun, but instructions are slim. Best free download I've seen.
Plus side:
If you are more of a sniper then a "guns blazing" type, you'll like this game. The enemy shoots quick and true - if you get hit and survive, don't bother looking for a med-kit. It's better to save often and be more careful. The reportedly unstable software has been running without problems on my older PC.
Minus side:
Some actions (like climb a ladder) are undocumented and required a little trial & error before I realized "U" for "Use" is universal for everything from climbing that ladder to frisking dead enemies for their weapons. I have been unable to get my team members to act as a group, although it appears that is an option.
Hints:
Scavenge all fallen enemies for weapons. The initial allotment you select will not last for many missions. Place your team members as close to enemies as possible and let the AI decide when they will shoot. That will save much ammo and eliminate many combatants. Use the (Space bar) often to get a map view that will show any enemies in range of your team.
Good luck, and keep your head down.