There is actually a context, but we didn't really have the time to develop it in game. Maybe we'll explore it later if we can :)
Yeah I get that it gets more difficult quickly, but it encourages the player to explore to get more upgrades. I guess the main issue is the 3rd area that is too long without a checkpoint.
Thank you for the compliment on the SFX :)
For the music, it's actually mixed in a dynamic way, lowering down when enemies shoot at you so the player can focus on the action rather than the music. There is some issues concerning the time it gets to get back up tho.
Thank you for the feedback! :D