Great game. Only suggestion is to make the magic / laser towers much tougher. They're a good idea to mix up the level design, but they're too weak to be any real threat. If you really had to hammer them, they'd create a lot more tension. I mostly destroyed them with stray shots while shooting at other enemies.
I'd like to see how many coins I have in total after every run, not just how many I earned. When I'm aiming for a certain number to buy an upgrade, I have to keep checing the upgrade screen to check my total coins.
I feel like there's more skill required at lower levels where you can actually predict the movement of the balls. The higher levels, and level 12 especially, are just luck.
Last boss has a pretty big blind spot. If you just sit over his head and have decent range, you can chip away at him without him being able to fire back. A bit disappointing.
1. Hotkeys
2. Speedup or quit level early
3. Automatic return to 'shop' screen after each level
4. Pathfinding for penguins to avoid obstacles (has anyone mentioned this yet ;)
I love the mix of money upgrades and xp for weapons. The money side adds a resources management element with the factories, but the xp side also encourages me to use different weapons and not just stick to one. Its a fantastic mix that works great.
thank you =)