It's a cool game! I think you made good use of the limited color palette; you mentioned going for an Apple II vibe, but it also vaguely reminds me of Gameboy games.
The mechanics are pretty simple, but you got good mileage out of them. I thought you used the light in some interesting ways, like the way different enemies react to it. I do wish that the light went out/came back faster than it does currently though. The blocks that toggle movement based on whether the light is on/off them are a little annoying to deal with given the 1 second delay between hitting the light button and the light fully vanishing.
I also got stuck for a while on the introduction to dashing, where you had to hit a button then dash through the door. I was trying to stand on the button, and then dash through the door after it had fully opened, but even dashing from the very edge of the button I couldn't make it. I didn't realize that I could step off the button as soon as the door had started opening and the door would keep opening; it felt a little off that using that trick was necessary at such an early point of the game.
That whole essay about minor gripes aside, this is a nice little retro experience.