This is a review for MAX, not MAX2 which falls short of being a great game like MAX was.
MAX is a fantastic game and there really hasn't been a game released that's quite like it. The base building, resource gathering, scouting and combat system are very well done and engaging. The best part in MAX from my perspective is the unit upgrade system - you can either buy upgrades for gold or you can research them. Buying them gets you a flat increase, say 1 more movement point, researching it gives you 10% better stats in the area you researched. There are no limits to how much you can research or upgrade your units.
Keep in mind though, the game has flaws, even fully patched it's not the most stable game in the world, you can run into a scenario where your savegame is unusable because the game crashes at the end of turn. The AI leaves a lot to be desired so it's best to play against several AIs. There is a multiplayer mode, but frankly the game is a bit too slow paced for it in my opinion.