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). Make sure to fill out your README with information about your game rather than just the folder structure. You can use all the information from your submission page: https://calaverite.itch.io/scram and add that in. Remember to fill out both of these when you get a chance.
Full browser window by default is great. The game idea and your take on the theme is interesting and creative. The first part of the game however is a lot to take in all at once. I'd start with a smaller "level" and have a tutorial style. Introduce new elements at each level to make it progressively harder. It's a lot to understand and the game board is so big right off the bat. The game would feel a little more managable.
My character also ran off the far right side of the screen... is that meant to happen? Looked funny regardless! I love the sound effects, add some music too in order to make the game more immersive. Is there also a scoring system or something you can implement too? (time, number of elements or similar would be good elements for scoring). Great job on your submission.