itch.io

Actually I just tested on my laptop and although better, there
are still situations where it simply can not work. Namely, when
holding diagnostically/things that require multiple keys to be held.
This is definitely an issue with some laptop keyboards, it works
great on my desktop PC & keyboard.
It also works fine on my laptop with a joypad.
I am going to do some research to see if there's any way around it.
I have seen this issue solved before by reading the hardware in a
more direct way on things such as the Commodore 64 but I'm
not sure if this is possible on my laptop's keyboard matrix.

Check this test page for N KEY Rollover:
http://gadzikowski.com/nkeyrollover.html
I can get 8 keys simultaneously but they're in weird locations.
(q a z w s c f . , /)