This is really well done and very entertaining. I love what you've done here and the ability to pause the wave to check on my buildings or switch them around as needed is really nice. It makes it more about strategy and less about twitch clicking abilities.
I like the graphics and how often you change them up. It does take a bit longer than normal to get a proper feel for the game, but no really an issue, just something of note. I enjoyed it though.
It's a solid start, but I agree with what others are saying. Hot keys would be nice, penguins tend to get stuck on ice chasing one target when others walk right by them. And I agree that either you should be able to sell old armor or if you by a lower tier armor it should reduce the cost of the ones ahead of it. Still, I enjoyed it and would like to see it grow even into a sequel.
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