I have a few things to say.
First, you should add an easy mode which gives the player 5 health at the start.
Second, I encountered a bug. I don't know how to explain this very well, but I dashed, and then AFTER I WAS DONE DASHING, I went through the laser without taking damage.
Third, the description for the heart in the shop is "Takes a LICKING." I am pretty sure that it is supposed to say liking.
Thanks for making this, it's one of my favorite games of all time!