This is such a short and sweet little game! The slimes is very cute, the gameplay is engaging, the core loop is simple to understand, and its fun! Good job! I'd say the game gets a bit unfair towards the end of the game as there is no way you can defeat each and every slimes before they get to your castle, but at least the game ends shortly after that! I think the game would really benefit with upgrades between waves and it would be a wonderful little tower defence game in no time.
Anyway, good job!