Just to note: there is an "Edit" button; triple-posting tends to be frowned upon around here ;-)
The sprites look pretty good, though they could use some polish. A couple of them (minotaur and imp thing) are a bit dark; some highlights could help them. Overall, the sprites could use a stronger lightsource, since they all seem a bit flat at the moment. Also, getting rid of the internal black lines might help them look a bit cleaner and perhaps read better. Good luck with this!