This is a screenshot I have taken of a ray casting first person shooter game I have created (Anarch). I made the whole game myself from scratch, including assets, and have released in into public domain under CC0.
<a href="//commons.wikimedia.org/wiki/User:Drummyfish" title="User:Drummyfish">Drummyfish</a>
<span class="int-own-work" lang="en">Own work</span>