it's impossible to 100% this game becuase you cant get all of the puzzle pieces

Actually, you can. I'm assuming you mean the puzzle pieces in the Attic minigame where the game crashes?

I was able to 100% the game at least 3 times and I happen to have a 100% save file of it right now. I'd already posted my fix on PCGamingWiki, but basically what you need to do is:

1. Do NOT use the vacuum while the cupboard is closing. This lowers the chance of the game crashing
2. If the vacuum stops working, bump into a spider while holding either of the vacuum buttons. It should be back after that.

It is still annoying though because sometimes it will still crash and managing the time is difficult when you have to deal with glitches at the same time. Nonetheless, I assure you that 100% is definitely possible in the PC version