Great game, but the strategy is pretty simple; (SPOILER, kinda) use the bayonet on the AR to basically plug up the spawn holes, take out the huge guys first, then the ranged/the green lumberers, save your ammo on the drones. The sequel should be pretty awesome. I'd like to see a bit more customization options; maybe put a bayonet on other weapons (pistol-knives are totally reasonable), armor customization, actual class development (don't really know about this, as I just had the big guy and 4 with AR's for the last levels, never even bothered buying the sniper).
The travel and battle sections are way too slow; waiting for the enemies to move is so tedious. A mini map during battles (maybe markers for each unit) would make it easier to move around the field. Maybe a pedometer in the travel section? Maybe on the map thing, have x days to travel from a to b. Other than those, the game is great. It plays a lot like frontier, except it is so much more complex; I love it.