Not really. The old TMNT site before Nick bought it used to have a great section that has a brief synopsis of every Mirage issue along with a few photos, neat stuff.
But for the most part, the characters look similar to other counterparts. Casey looked a lot like his Playmates toy counterpart, same with Rat King and the Triceratons (to a lesser extent). Utroms, Shredder and Foot you've seen. Really the only other major classic well known character I can think of is Leatherhead and he looks pretty much exactly like his 2K3 counterpart, same for Fugitoid. Karai I guess has a unique look but she's not that different than other incarnations. Beyond that the rest of the characters in the Mirage run are pretty much exclusive to Mirage.
Likewise, there really wasn't a "Mirage style" so much because E&L sort of refined their style and drew very differently at times and then subsequent material was largely done by different artists, some for more issues than others (Lawson did the drawing for all of Vol 4 as an example).