If you’ve ever wondered how Nintendo’s classic games evolved before they reached store shelves, you might have a good chance to find out. According to VGC, (via Eurogamer) a “gigaleak” of Nintendo art assets and source code from the mid-1990s has surfaced online, revealing prototypes of games that looked and behaved quite differently than the final products. Yoshi’s Island (above) had a different interface, music and mini games, while Super Mario Kart had no drifting. Even the once-abandoned Star Fox 2 (eventually released with the SNES Classic Edition) was going to have a human pilot at one stage.

Other tidbits include alternate artwork from Super Mario World (Bowser might have had visible legs) and “Zelda 3,” a very early engine test for what would become Mario Kart 64 and source code for Star Fox 2.