This is a really fun little game, that works with the theme well. I like the gameplay mechanics and the increasing difficulty feels well balanced. The sound and artwork are good too - I like the overall design, the UI was good although a little buggy with the shop buttons as mentioned by others. The look of the "Fight" & "Shop" buttons were a little bit out of sync with the rest of the game's style and if it hadn't been mentioned elsewhere in the comments I wouldn't have known what the shop button did - but that's probably being a bit picky as overall it was an enjoyable game - well done!