I caught a hint of boktai as well, when I saw these. It's hard for me to give any crits though, 'cause there's so, well, not a lot. What's there looks good, but it's hard to tell how it'll fit in with other tiles, how it'll tile at all (becasue A)I've never done tiles in this perpective before, so seriously, I have no idea and B) it's hard to say, atm how gridded it'll look), etc...
But yeah, like adarias said, what's there is looking good. Keep at it.
Oh, and welcome to the boards!