Onirism follows Carol as she pursues her stolen plushie, Bunbun, through Crearia, a strange world shaped by imagination. Its colorful settings range from candy-colored forests to pyramids and a moon base, giving the adventure a deliberately surreal backdrop. The premise pairs a high-energy heroine with a personal rescue mission, while bizarre creatures and hidden secrets make exploration part of the journey.
Combat and movement share the spotlight: Carol can blast enemies with an extensive collection of weapons and gadgets, platform through varied environments, and ride vehicles including a plane, hovercraft, and mechs. The game also describes puzzles alongside its secrets, while its large bestiary and roster of bosses make confrontations a prominent part of the design. Costumes add another playful layer, letting players change Carol’s look as she travels through the dreamlike worlds.
Onirism is presented as a single-player adventure as well as a game with local and online multiplayer options, including competitive battles and cooperative boss fights. The contrast between a story-led platforming adventure and multiplayer possibilities is part of what defines its identity.