Thanks !
At first, I only design the last boss that I split in different parts (Head, Guns, Shield, ...).
Then I disabled each parts but the head create the first boss, enabled some others for the second one so that you learn each pattern at you own rhythms. Thus, at then end of the game, you already know the last boss patterns without even starting the fight (but it is still difficult !)
GG for your time !
I think you have the best performance I know, it took 120 sec for my friend to reach the end of this game , GG !