Nanosaur is a 1998 Macintosh game by Pangea Software. In it, you’re a cybernetic dinosaur from the future who’s sent back in time 20 minutes before a giant asteroid hits the Earth. And you get to shoot at T-Rexes with nukes.

Nanosaur was bundled with the original iMac and ran on Mac OS 8. It’s also notable for being a prominent showcase of QuickDraw 3D’s capabilities, which was Apple’s high-level 3D graphics API during the 90s.

In 1999, Pangea released Nanosaur’s source code to the public. This port is based on that release. (Note: the restrictive terms in that link are ancient — Pangea does endorse the existence of this port today.)