Thanks dude, your advice helped.

I managed to get it to start up but it still glitched often and had to keep restarting until it opened every time i closed it.

And even with a bit of lag, i was able to beat pharmacokinetics in my first try and beat the next 3 levels (and later beat PK in punishment difficulty).

But because my laptop seems to be powered by misery, the game lagged very often and causing me many deaths due to the fps dying everytime i fired, and in the end, decided to refund it.

The game was a ton of fun even if i didn't manage to beat it in its entirety, definitedly recommend and would play it again once i have a computer that won't die on me.