> Bouncing on collision
What are you using to make this? My tip here would be to push back just after you've applied movement within the same tick.
Also, you've got a few issues with your camera - I'm seeing some rather nasty subpixel artifacting. If it's Game Maker you'll want to manually set the camera left/top - try something like view_left=floor((x/4)-((160-60)/2)); if you are using, say, 4x upscaling.
What's the zoom level here? With 8x8 tiles you'd fit 20 tiles wide, and w/o HUD 18 tiles high. If what you have is roughly the zoom level you want, consider going for 16x16 tiles (on real HW it'd be made up of 4 8x8 tiles).
By the way, join us on Discord, I or someone else could possibly help you out a bit with your tiles. I recommend using more colours per tile here.