This is a game I feel has promise. Great fun with two different games in one - kind of. Very clever and I think you did a good job with the general design of this game!
I have some feedback though. First, I think you should just get rid of the lives stuff. I get that you want to make this a highscore-based game but I feel like lives is a dated design philosophy that only worked back in the arcade-machine days when you wanted to pump coins out of players. For this game, I think you could get away with just taking away score by dying and give the player their final score at the end instead of on death. It would work fine, more people would also more likely finish the game with a design like that. Personally when I die in a game like this that uses lives, I just stop playing. Because let's face it, it's a small game on the internet - people quit fast, and you want people to play your entire creation!
Then there's smaller gripes. Like, I think it's a mistake to have the player have to hit the up button on impact with the springs - rather than just allowing the player to hold Up while landing on it. You could make the argument that it adds fun difficulty, but I actually think it does the opposite. With simpler game mechanics, you can gradually make the game harder with level design. The more accessible you make the controls, the more creative and crazy you can go with the level design towards the end. Accessible mechanics doesn't have to mean boring!
Cool work on this though, I really appreciated this game. I hope you keep on posting on here.
Oh and - add NG API highscores next time! It really helps boost the engagement on here I've heard!