@Kyo1995. It's called a JOB. The developer won't starve if kids aren't paying him/her their parents money. And idk why everyone is yelling about it either. The only things that you shouldn't have to buy are upgrades for the towers. Level 31 you can achieve yourself, The double money mode wasn't in any of the old ones, so just act like it's not there. Quit bitching and play the game. 5/5 Btw.
Something I found out, you can combo some of the firing upgrades. I don't know if this is general knowledge, so I'll say the ones I know. Pick of a Megaton laser then a double fire and it will shoot 4 lasers at once. Or if you pick up an Ion wave then pick up Tetra fire it will shoot three waves at once in a sweeping motion. Pretty cool.
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