You have a README which is great, but you'll need a License file as well (these are two main criteria for open source category). You can always spice up your README with screenshots, gifs, and emojis if you like.
Love the artwork, full browser mode on startup is great. I like the sound effects and music. Smooth game, smooth controls, very intuitive, and having the sliders at the top are great.
I like that you introduced dynamics with different numbers and sizes of blocks. It also looks like the games are autogenerated so you can't just learn the block placements which is good. Nice work on your submission.