There's a serious problem with 4-3. A lot of the time all I'm getting off the conveyor are spells, and they aren't strong enough to kill the oncoming enemies, making the level literally unbeatable.
I think the concept and the gameplay itself are good, but I think the game needs stuff like levels or time limits/minimum matches, that kind of stuff to make it not boring.
Overall I think it's a good game. The only real gripe I have is that the bosses tend to have health pools so large that it takes longer to kill them than it's fun to fight them. 5-1, for example, was a very simple fight, just shoot the core, dodge a few bullets and use fireworks to clear out the trash enemies. But with the boss having 500+ hp it felt like it took forever.
Mekill--- It only takes 4 shots to kill the boss once your gun is fully upgraded.
Frozen--- When he starts shooting rapidly you have to stand directly under him.
 "Training Grounds"){kind=icon}
 "Paladog"){kind=icon}
 "Magic Fishing Atlantic"){kind=icon}
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 "Village Tower Defense"){kind=icon}
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 "Disaster Will Strike"){kind=icon}
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 "Johnny Upgrade"){kind=icon}
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I imported them just for this game. You see the lengths we go to keep you entertained.