(I'd like to preface this by reiterating that this person is not Darkpixie the player.)
Hello. I am the head pixel artist for Bones Underground. I was unaware of any inappropriate usage of artwork by our game. I would be happy to discuss this matter with you, but I would like to say that some of those monsters were made very clearly by different artists with wildly different artistic styles. I am also mildly suspicious that you would ever have pixel art in the form of a .PSD file, as photoshop is generally poor for pixel art and I don't know of people using it. (Most of the monsters you described were hand pixeled.)
(Whether that is an instance of naming coincidence remains to be seen. If you're throwing out false claims for the hell of it, as has previously occurred, I will be very put off by the waste of my time.)
Anyway, I naturally take all claims of art misuse very seriously, and I will work with you to resolve the problems if they are legitimate.
Go ahead and send me an email at Cirrasbu@hotmail.com and we will go from there.
The cake is a lie.