very, very, very nice. I really like the clean aproach ommiting outlines almost completey. I dont really see much of this style in that megami tensei link you gave us. When I see this I think more of the medium-sized CV:Symphony of the Night bosses, Pocket Fighter portraits, Some street fighter2 and Alpha portraits, some Dark Stalker portraits.....and Waku Waku 7......you guessed it, I tend to look for games that dont use outlines =)
This godlike cow with a penis for a tail is great. is it's hind half some kind of parasite? since it's the one with the peni and it's got tendrils all over it, it almost makes me feel as if it's a sacred cow that has been possesed by some evil plant-penis virus or something :p
that "android" looks more like some paranoic dream to me. I really dont mind at all that he springs right out of the floor, that makes him seem more like some mad amputation related delusion...which is cool in my book.
The construction of this one seems to be the poorest of the 3, it's ok that his musculature is exagerated but something about the way he is drawn makes it look like he has no real volume and is actually flat. One thing I can spot right out is the way the neck is SO ambigous, the muscles you specified in the botton of it imply it's turning to (our) left, but his head is actually turned far to the right (the fact he's doing your typical break-the-skull style anime scream must have an influence too). For the arms, I think the triceps look a bit disjointed from his chest muscle (forgot the name, so sue me!) it kinda makes it look like the muscles are just for show and dont really power his movement.
I really enjoy that reaper rider, that round, simple shape you gave to his ride really puts the attention on the awesomely done rider, and that crazy alligator with horns below him. This one has a very nice sense of movement; Have you ever tried animation? to me it looks like you could have some wild fun with it
My main crit is...you sure you want to waste all this art in some puny little RPG? RPGs strike me as awfully unimaginative in general compared the kind of concept art that goes behind them