Please give me some feedback on my first-person-shooter engine

Here is the link to my project:

I would like some feedback on it if you don’t mind.
If you find any bugs, please report them.

Two things I’d add are mouse locking and being able to press multiple keys at once.

The mouse does lock but on user click. You have to click the screen first. Pressing multiple keys at once makes a huge bug occur of you being able to travel through walls.

Hm, alright. I assume you’ve looked into why that bug occurs.

Make sure you don’t just run the pen here. That’ why it isn’t working. Go over to the link and try it.
Press the “Edit on codepen” link and you should be there.