Well, dang it. I tried Pre1 today, after years and years of not playing it, and couldn't complete it! They finally got me near the end of the seventh (and final) level
This game will always have a special place in my heart, as it is the first TRUE game I've ever played, and one of the hardest nonetheless.
I remember when I first completed the first level

and the thrill of discovering what lay beyond, all those silly penguins and stuff

It CAN be completed in under 20 minutes, if you know what you're doing
Anyways, <3 Prehistorik
