Play Itsudemo! Nyan to Wonderful (Japan) Online

Itsudemo! Nyan to Wonderful is a Japan-only Game Boy puzzle game released in 1999 by developer/publisher J-Wing. It arrived late in the handheld's life, when many developers were still finding creative ways to use the hardware for thoughtful, compact experiences rather than flashy action.

You control a round, cheerful cat whose main task is to push blocks onto switches to open doors and progress through single-screen stages. Each level is a self-contained puzzle, requiring you to navigate around enemies, avoid pitfalls, and sometimes use items like springs or teleporters. The difficulty ramps up steadily, introducing more complex mechanics that demand careful planning; one wrong push can force a restart. Playing it feels like slowly untangling a knot, with a real sense of satisfaction when everything clicks into place.