These are the icons for close/minimize from the game Into The Unknown. You may use them for your own game
It contains close, minimize and maximize as well as hovered versions of each.
Attribution Instructions:
As a courtesy please E-mail the FRPZ team at taurusxyz@yopmail.com or unirail@yopmail.com. Please write the name of your project and what it will be used for. You don't need your permission but we would like to keep track of use in case of licensing problems and the like.