Great game. Play the sequel, if you haven’t, free on Steam:
https://store.steampowered.com/app/2645580/Free_Stars_The_UrQuan_Masters/
I think sometimes loose noises may just be plastic tabs, but doesn’t hurt to check.
One thing you can try is DeoxIT. It’s a non-conductive corrosion cleaner than you can go nuts with on contacts.
It’s expensive, but this is enough to last you roughly forever unless you're a hardcore electronics refurbisher (~1250 drops, you’ll use just a few at a time):