Thanks all!
Your positive feedback gave me additional motivation to move forward!
By the way, I wanted to thanks Clement particularly since he gave me the idea with his
Choplifter-like.
About music / sound I already put some (on player fire, on ennemy fire and on explosion). I'll try to add some helix sounds as well, but sounds are consuming cpu, and I'm already seeing concerning pikes (see number next to ammo bar), so don't expect music
About moves, I'm not 100% convinced by the way I'm currently using buttons:
A to shoot, B to land (that's good).
If A is pressed, helicopter direction is not changing (=straff).
This means Player need to shoot to avoid changing direction. I'll try to replace A per B since we can only land when copter is not moving...