Thanks a lot for playing and for the very detailed comment. It means a lot, your entry was exceptional.
The game was initialy coded for AZERTY keyboard and I'm afraid that "strafe with QE" must be a byproduct of that, the tutorial was added quite late into the game.
I'm really glad you noticed how compact I tried to make everything. With more time I could probably divide the size of each level file by 3 or 4. I really enjoy useless optimization and I was pretty disapointed when I saw how long levels transitions are on browser, I guess JSON files were still too heavy to be opened on the fly.
Again, thanks for the kind words, I probably won't upgrade the game too much beyond bugfixes but I'll definitely reuse some of the system I made for it. Have a nice one.