Uxtal is such a great platform to develop as a rock solid ABI. Very lightweight and stable, yet niche, it really feels like a counter-culture movement to the modern slop, vibe coding and JS that the mainstream is currently at.
(For the specific application of games / graphics, I'd go with libSDL. Version 1.0 was released in 1998, and my current machine still has "libsdl1.2-compat" installable and supported. But I don't play games much so I know much less about those.)