It's a pretty good game in the super hexagon tradition of difficult, twitch reflex pointsathons, but is ultimately let down by some strange design decisions. The exponential bonus for collecting succesive coins means that the deeper you go, there's almost no point continuing once you've missed a coin, given that the game's difficulty ramps up so significantly and your bonus is reset to zero. This fault is further exacerbated by the tendency for coins eventually to appear in uncollectable scenarios, where an enemy spawn or platform disappearance makes it impossible to continue your sequence, and that's not to mention that the relative speeds of square and coins in descent makes it all but impossible to snag a coin once it's started to sink to the floor.
Perhaps if your bonus halved when you miss a coin, rather than resetting to zero, there would be more incentive to continue in those situations. Equally, some ability to speed up the square, particularly in descent, would make the coin's falling off-screen slightly more fair, otherwise I'd be inclined to alter the way it departs if it's genuinely supposed to be uncollectable at that point.
Lastly, part of the fun of twitch reflex games is the instant loop of death and restart, which makes that cycle in Super Hexagon and Super Meatboy frictionless. Here, however, the R key takes you back to the logo screen and then the title screen, while killing yourself to abort a run is quite fiddily.