|I don't remember pyramids, but it kind of sounds like Boulderdash. That was a DOS game where you had to dig through the dirt under boulders to collect diamonds or coins or something. The goal was to collect as much as you could without getting crushed by a boulder and to make your way to the exit before the clock ran out. It was a sort of boulder puzzle all on one screen.|
If that's not it, have you tried the internet archive. There are lots of old games there, some for download and some you can play right in your browser.
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