Awesome concept! Liked the simple controls and it was easy to keep playing.
Nice music and sound effects.
Could add some more squishy animations for the center character.
For me it took some time to notice that the 4 hearts are for the bouncy character, and not the center one. UI layout may need some revisions to communicate that.
You could use some pixelated shader / post process to make the game/display area look pixelated. that would look really cool. I've seen some pixelated post process tutorials on YouTube, they might help.
Overall a fun game.