Dang, there's a lot here! The presentation is really solid, and all the roguelike elements are present and correct. I initially thought the lack of enemy variety was a shame, but on reflection, I'm really glad I didn't have to manage different enemy patterns.
Two tiny nitpicks: the key prompts don't change when you rebind the keys, and config changes aren't saved when you refresh the page. Other than that, it's really solid.