I've found ZOO keeper badge, +300% exp for animals, got it after Chick level (Normal, 6th page, 2nd row, 4th puzzle), then I played animal levels (you can see by names)
Your soldiers: Riflemen and Marksmen have most health, AA and Automatic Riflemen much less. Granadiers have no health :)
Rockets target always 1st enemy (closest to bottom of the screen), including boxes, Marksmen stick to target, will change it only if: 1) it's a building and a vehicle is in sight 2) the target is behind them, they can't shoot backwards. They also pierce targets, so overall damage is highest if you use it well. I find it easiest to play with full Marksmen team (4km easily) OR 50-50 Automatic and AA (3km easily).
Herioc charge? only for fun or for boss ;D. While napalm relies on team size, air strike is wider and easier to use, but has bigger cooldown. Minigun is nice, but I prefer shotgun in story mode and bazooka in endless mode.
I suggest you don't buy granadiers, they waste spawn. Your jeep makes it faster to reach the end, but harder to pick up your allies. Future armor is exellent, but your allies start with low hp.
I wish I could turn off upgrades...
I use EMP only when I hear Kamikadze men comming. I love their screams. And a piece of advice: lean out of your hole to use granades/health packs when you're under bullet shower. You save time when you can't shoot and troll your enemies ;D
It's a good, challenging game, I don't get it why you're complaining? the only thing I'd add is something to make it easier to gather energy after you defeat the last boss or something.
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