The artwork is minimal and looks to be phoned in/asset flipped (not a surprise, this is Piece of Voxel we're dealing with).
There's no working full screen mode, in fact, if you hit alt+enter, Piece of Voxel actually go out of their way to insult PC gamers by telling you they won't allow you to try switch to full screen ("Don't even try, i won't let you do it), then terminate the game. Insulting your customers is not a winning strategy, but then this is Piece of Voxel, who make a living stealing other people's work and trying to sell it on Steam as a scam. What's that? Oh yes:
Piece of Voxel are known asset flippers and have previously taken other developers work and put it on Steam in an attempt to scam gamers and get paid for someone else's effort. An example of Piece of Voxel doing this is Top Truck Driver, which is really "Hill Racing Template", written by the actual developers, Janko Knez. Also, Hoples, which is really "Pixel Adventure 1", developed by Pixel Frog.
Asset flips are harmful to the gaming industry. They're nothing but cash grabs, and they harm genuine indie developers by reducing their visibility on Steam. Because this game has all the same low quality as an asset flip, as well as the other problems with it, it's impossible to recommend.