It does not affect your computer and can be uninstalled at any time. In order to play, you will need to download and install the RTP (Runtime Package). Instructions: Ao Oni was created with RPG Maker XP game engine.
Check the downloads page for more information on which versions require the RTP. Only versions of the game made in RPG Maker XP will require you to download and install the RTP (step 1 above). Welcome to the installation guide for Ao Oni, here are the notes:
