Alpha Waves, released by Infogrames in 1990, is a landmark of early 3D gaming and is often cited as one of the first true 3D platform games. Set inside an abstract world of filled polygons, it has you bouncing and flying through a series of connected rooms rendered in a way that was startlingly ahead of its time, when most action games were still strictly flat and 2D.

Its filed genre of logic/puzzle reflects how much of the challenge came from spatial navigation, using momentum and jumps to move between platforms and passages in fully three-dimensional space. The look is stark and geometric rather than realistic, but that abstraction is exactly what let it push the hardware into genuine 3D. It's less a game you play for polish today than one you appreciate historically, a pioneering step toward the 3D platformers and worlds that would dominate a decade later.