@Wolod: Thanks for the interest in my game, but don't expect too much ;-) Sorry regarding your problems. My first guess is, that your machine is missing the .net runtime(minimum version 4.5 is needed). Stupid of me not to think about this before releasing (my first monogame release). Maybe I will have a look into including an .net installer later.
@Roh & supersysscvi: Thanks for checking out the game and your kind words. Means much to me.