Xexyz

Xexyz is a 1990 NES game developed by Atlus and published by Hudson Soft (originally released in Japan as Kame no Ongaeshi: Urashima Densetsu). It fuses genres unusually: odd-numbered stages are non-linear platforming areas full of exploration, NPCs, shops, and fortress infiltration, while even-numbered stages break into pure shoot-'em-up.

Across islands, underwater ruins, sky temples, and mechanical citadels, players upgrade weapons and armor and unlock new paths, giving the game a distinctive Metroidvania-meets-shmup flavor and a lasting cult following.