Best way to get Cheevos:
1. easy is easy
2. medium --> just build fully upgraded dart monkeys
3. hard (apopolypse) --> build a magic monkey, eventually upgrade him to have explosions, then build fully upgraded dart monkeys around him and keep building the dart monkeys. Wave 30 will pass in no time
4. Build ninjas, dart monkeys, etc. until you have enough for monkey farm. Level 1 monkey farm pays off in 15 rounds, Level 2 in 11 rounds, level 3 in 10 rounds, etc. Don't buy banana republics, just stack level 3's. Do whatever you normally do to get to high rounds, then save up for super monkey which will eventually become super monkey totem. Basically just build as many of those as you can late game. Also, be prepared round 63 for a super lead balloon rush for which you'll need more than super monkey's, you'll probably need a few missile launchers to break them up. After that I found that as long as I kept building monkey temples, I would win every time. E..Z
This game is rather silly sometimes...at later rounds (such as 63 on hard mode) you go from killing everything so fast that they can't even leave spawn to totally overrunning your position in about 5 seconds. There is no inbetween, no time to react
The REAL secret to the hard badge is that you have to start each wave in the one of the four corners - for some reason it helps slow down the wave spawn time. Also I would try messing around with the quality settings to slow down the frame rate so that your claws don't pass through zombies as much. Finally I didn't realize this earlier but your upgrades in-game do not transfer over to the zombie mode.
This game sucks. It's just a grinding simulator, a game that takes no creativity to make and no intelligence to play. The minigames are boring asf, the combat sucks, and the fact that EVEN WHILE HACKING THE GAME I couldn't beat it because it just goes on forever. The game feels more like a heroin addiction than playing a flash game. trash, 1/5