Open Hexagon freely states that it is a clone of Terry Cavanagh's iOS mind-melter Super Hexagon, but on PC. The developer of Open Hexagon, Vittorio Romeo, says that he secured permission from Cavanagh to make a game inspired by Super Hexagon, and Cavanagh says he's "basically all right with it." He'd probably be totally all right with it if Romeo hadn't beaten him to a PC launch.
"I'm a little upset that he released it before I had a chance to release Super Hexagon on PC myself," Cavanagh tweets. But, overall, he says Open Hexagon is "not bad at all – the harder octagon stage was pretty cool. I also like the death effect."
So, no harm, no foul. Cavanagh even posted Open Hexagon on his Free Indie Games blog, writing, "This is probably the closest I'll ever come to posting my own games on this site." Besides, Open Hexagon is free for PC. Check it out right here, or play Super Hexagon for $3 on iOS (or regular Hexagonfor free).