![](http://4.bp.blogspot.com/-30WjtUJZIRs/T_yLIwiifAI/AAAAAAAABEU/qTJIwv8M9aM/s1600/fourkeys.jpg)
Four Keys is a short single player UDK-powered puzzle thing by Andrew "Mclogenog" Yoder. (Mild spoilers after the jump...)
It's a bit like Antichamber and Ian Snyder's Feign in its interest in non-euclidean space, but its short length makes it more complete-able than either, and I think the flat color treatment of surfaces helps the shapes pop out / makes it more accessible. I think it's perfect for some sort of gallery setting.
Make sure you remember the title as you play it...