Despite moments of brilliance, this game is exceptionally buggy.
Generally, ARMA tactics is a decent, but limited, turn-based tactics game. The turn system, action points, and interrupt systems are all pretty standard but well implemented. The level designs are OK and the graphics aren't bad either. Unfortunately, all of this is rendered moot by an avalanche of bugs that make the game nearly unplayable. Little things like:
1) The "Continue" button (which should continue your game from the last mission you were on) on the Main Menu doesn't work and typically just hangs the program.
2) Building a custom mission and selecting "Random" for the map type always results in the first map (African Town I) being chosen.
3) Custom mission type "Terrorist Hunt" results in the terrorist you are hunting LITERALLY DISAPPEARING OFF THE MAP, making it impossible to complete the mission.
4) Multiple bugs in campaign missions making them impossible to complete without replaying repeatedly and hoping not to encounter the bug.
5) Weapon modeling is nearly non-existent. While the sniper rifle has a longer range and appears to crit more often, M-4s and SAWs do about the same damage at about the same range... with no suppress function for the SAW.
Bottom line: at $9 it is OK, but extremely frustrating. Suggest X-COM or one of the Jagged Alliance sequels instead