Interesting take on the theme
I think a lot have issues with the controls - me too.
If you dont want to use the mouse thats fine but if you don't I would recomend that you use W/S for forwards/backwards A/D sideways and Q/E for turning...
At first I thought the birds where my friends - with the little hearts until I died and realised that it was dmg.
I got up to the 2D flying gravity part and managed to stay a float for a while but at some point I always just fell or foated to the top without being able to stop that.