A pretty cute little game, well done! I kind of lost track of time for a bit there haha, the music fits the vibe quite well too!
It felt like that "health' bar on the right was dropping down faster the longer you got right? It felt a bit too punishing, e.g. I wasn't really making any mistakes and was hunting down closest mice without boosting and I still died. Also, it felt like boost decreased health faster but I'm not sure if that was the case.. One way to make the game more difficult without decreasing health faster would be by introducing more complex obstacles over time to loop around so the player is more likely to make mistakes.