One-upping Gamma World, Altered Earth from Avalon Game Company is a post-post-apocalyptic RPG based on Dungeons & Dragons (4th Edition but not under license).
Out of the darkness came the rise of the warlords, invincible masters of the old technologies. Under their reign, a new age has begun.
Among the character races available are human, android, cyborg, and gene freak; the classes, athlete, diplomat, and specialist. “Experiments” are the analog of rituals, but for tasks making use of ancient technology.
Just released for the Altered Earth game is Heroic Tier Threats, a collection of mutants and other enemies.