Nice! I got killed by the cow (in just one hit? cruel!), then I guess one has to start from the beginning again, so left it there. But it was a good time.
Visually, there’s mismatched scaling all around. Doesn’t impede gameplay or anything, but it’s a sloppy look. You ought to scale all the sprites by the same amount (or even better, don’t scale anything until the very end, just the main framebuffer).
You really do need to credit all of the 3rd-party assets.