BoxBoy! + BoxGirl! is a puzzle-platform game developed by HAL Laboratory and published by Nintendo for the Nintendo Switch. It is the fourth game in the BoxBoy! series a follow-up to Bye-Bye BoxBoy! (2017) and is first installment to be released outside the Nintendo 3DS. The game features a two-player multiplayer mode a first for the series. BoxBoy! + BoxGirl! was released worldwide for the Nintendo Switch via Nintendo eShop on April 26 2019. It received generally favourable reviews from critics with the addition of multiplayer being highlighted though the game's difficulty divided critics.