Mountain is a simulation video game developed by David OReilly and published by Double Fine Productions.

[1] Upon starting the game, the player is asked to draw responses to a series of questions, described by OReilly as "more psychologically invasive than anything Facebook wants to know about you".

[2] The game uses that input to generate a model of a mountain, floating in space, surrounded by a small sphere of atmosphere.

[6] The title was initially released on July 1, 2014, for Microsoft Windows, OS X, Linux, and iOS platforms;[6] an Android version was delayed until August 19, 2014, due to the cost of getting the Unity plugin for the operating system.

[8] OReilly had initially envisioned the game to run as a background application for personal computers, and thus had not spent a great deal of time optimizing the iOS version through the Unity engine.

However, within a week of its release, Mountain was one of the top-selling titles on various app store charts, prompting OReilly to develop more optimization for the iOS and pending Android versions.

[10] The game was generally praised by reviewers as a novel concept,[1][11][12] though because of its limited interactivity, many players were discontent, comparing it merely to a screensaver.