This is a good first game, I enjoyed the movement mechanics especially with the dash. It's ok that you borrow assets, I used to do that when learning godot 3 years ago, but I recommend practicing to draw some assets using pixilart.com as it's quite easy to use and fun. My advice is to draw in a 16x16 or 32x32 pixel size and you can also look for tutorials to help but overall, good job and congrats on making your first ever game!
