Baba Is You is a puzzle video game created by Finnish independent developer Arvi Teikari (known professionally as Hempuli).

The game centers around the manipulation of "rules"—represented in the play area by movable tiles with words written on them—in order to allow the player character, usually the titular Baba, to reach a specified goal.

In each level, the player is presented with a one-screen puzzle consisting of various objects, characters, and movable word tiles.

It is, however, possible to use certain properties that function even without IS YOU objects (such as MOVE or SHIFT) to create a setup where an IS YOU rule is broken, then put back together later on or even at a separate location.

This sparked the idea of creating a puzzle game where the player would push words to form rules.

Initially, each object was supposed to have intrinsic properties (e.g., ice would melt in the presence of lava) that could be disabled using the word "NOT".

[8] Teikari stated in 2017 that he planned to release the full game in 2018, and placed a development version of the title for download at itch.io.

[10] Baba Is You was released on 13 March 2019, via Steam for Microsoft Windows, Linux, and macOS, and on Nintendo Switch.

[3] Pocket Gamer was similarly positive, describing it as a "ridiculously complex puzzler that has you questioning not only every decision you make, but how anyone managed to think up something so bizarre", and concluding that it was one of the "most inventive, exciting puzzle games you will ever play.

It's beautifully simple in its graphics and its core design, but it'll make your brain hurt with how nonsensical the solutions appear to be".