This is certainly a unique concept, I haven't seen someone make a more addictive version of googles dino runner yet! The focus-splitting gameplay is really neat, and presents a good level of challenge. I like how the tempo slowly increases, it leads to a nice difficulty curve. The art style and story are cute, and suit the game well.
A few people have mentioned a grace period after death, which I think is a good idea, as a second or two to recover the tempo would be most helpful. The sound effects are fine (though a death sfx would be nice), but the mixing could use some work. The footsteps overpower all other sounds, and it's a bit headache inducing when you're straining your ears to hear the bounces. A few people have also suggested adding music, and whilst some ambient sound would be nice I think there is a high chance that the music tempo might clash with the bounce tempo, so you probably made the right call leaving it out. A little additional detail that would help is the ability to press space to restart. The game mostly does not require the mouse and so it's a little odd that it's suddenly needed to restart after a death. It's a minor detail but would help the overall polish and increase the games addictive qualities. I'm also uncertain as to why the user needs to hold the d key to move. There isn't really a need to ever change directions (that I found at least) and you could simplify the controls down to two buttons by having the character always walk when bouncing, and modifying it to a two button game would make a mobile port easier, if that was something you were interested in. Given I found myself holding d the entire time I don't think this would take away from the games challenge.
Overall the core of the game is great, and really unique. With a bit of polish this would make for a great time-waster! Well done :).