Too easy. Got bored with click spamming on the beginning of map 2 and gave up. Still, better than Last Stand 2, so 2/5. I'd suggest more variance in zombies, and possibly a weapon upgrade system.
Fun, except... can't turn off screen shake and it becomes very annoying. Also, the bosses kinda suck. I think you could draw a lot of inspiration from 2D scrolling shooter bosses to make more interesting ones.
I'm on world 53 and am falling asleep from pure boredom. I sit here and send 3-5 waves at a time while upgrading 2-4 gems and easily win. Nothing important changes between levels and the only fun ones are arcane guardian. Just not worth the mind numbing grind to get to the end of the game.
Only hard until you get up in level a bit, then it becomes trivial and boring. The different map types don't offer enough variance to make them worth playing.
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