Actually, your game does not even work in non-strict mode. I turn the game on and click RE/Start and it lights up and plays a tone for the first round. I click on the correct button and the console shows “wrong” and the game keeps lighting up the same button and playing the same sound, no matter how many times I click the correct button.
At this point, you need to figure out the basic play mode first.
Another issue I noticed is that the button lights up first and then plays the sound instead of both happening simultaneously.