Wow, I wasn't expecting that much, you're amazing! For the dash, the direction of the player's movement follows the mouse, but it may not be as intuitive as I thought.
for the game window, i will make it scaled, but i didn't knnow how to do it for a beta, and i think it's not that bad for a beta? but i will fix it for the main game
for the jumping part, i am not sure of what you mean, like do you mean platforms at very different height? like lets say one at 1 meter, and another at 4 meters? so it would be more like platforms in hollow knight, like, the world, would be less flat?
also for the projectile of the boss, your idea is really really really great, I think i will add the knockback and the immunity for 1 or 2 secs, just the time for the player to move, and i think about adding a flash effect to the projectil, like before the launch, the projectil would go red, also, thanks for sharing the colision bug, it help a lot!
I was thinking about adding an attack up for the player, but didn't exactly know how to implement it to be nice for the player, as the dash direction is also the mouse, i should have did like hollow knight, when you can attack up by pressing up arrow. I will add it in the future.
thanks again for your feedback, it help me a lot!!