I feel like less is more, honestly. I can tell there was a lot of effort put into the graphics and music, but I feel like they distract from the gameplay and make it feel soulless. To be blunt, you had me wondering whether this game was a mobile game industry plant posted on Newgrounds to get awards, especially since I know Suika Game is a hot trend right now and lots of companies want to capitalize on that.
The rat mechanic is a fun and creative addition for a Suikalike such as this, including the need to interact with what's normally a static game background. I feel like it needs some balancing, though, because there's not much reward for waiting as long as I do to get all five rats. So I'd recommend either making the requirement a smaller number of rats (as another user said), or have the rats cause a bigger rat-splosion that will take out multiple cats.
The basics seem solid at least!