Okay, I have a decent computer (preface). Then stage 7 hits and I get rushed with probably 200 air units. Now, I understand that this is supposed to make it a challenge, but either the game needs to handle this better or get rid of it entirely. I'm lowering my rating to 3/5 for this horrible design.
A hint to all players: The strategy that I used to beat the game was this: Start with elves (ranged general). Then be sure to upgrade weapons on as many units ATTACK as much as possible. After the first round, by 2 crossbowmen. Then buy catapults (2-3) after round 2. After round 3, get 1 more catapult and upgrade everything as much as you can (fore go the catapult if you can't afford it after upgrading). By round 5, you should have 7 catapults, 4 crossbowmen and your general. Then you just push damage as much as possible (armor too, if you have extra money). I took the goblin-orc-troll path.
Ranged units are good because they don't get hit by counterattacks. Be SURE to get the +movement skill on the catapults on the first level up.
Aaannnd now I'm pissed. The last two tracks (the only ones I have uncompleted achievements for) now refuse to work, or even load properly. I can't play anything but the last track (no matter what I select, it becomes that one) and when I go to it, the race won't start. The lights don't even appear.
 "SHIFT 4")
 "Black Navy War")
 "Battalion: Arena Beta")
 "Pirate Defense")
 "I'm AFK please don't chat with me(mod help)")
 "Spewer")
 "Sonny 2")
 "Fantasy Kommander")
 "Desktop TD Pro")
 "Marshmallow Saga!!")
 "Remnants of Skystone Alpha")
 "Space Mutants FROM SPACE!")
 "Exorbis 2")
 "Penguinz")
 "You Have To Defecate Upon King Bhumibol")
 "Drift Runners")