Ah, really? About XMen 2, I'm really surprised that a poster here and the topic creator aren't fans of it. I purchased it at a Pawn Shop(like I did with so many other Genesis games) and was pleasantly surprised how smooth and relevant the game played by today's standards. The first XMen game was pretty difficult, but it wasn't "unplayable" by any stretch of the imagination. Using Nightcrawler's teleportation move to create your own shortcuts in some of the tougher levels was a big highlight for me.
With that out of the way though, I'll have to name my favorite Genesis games besides XMen II, assuming you need more ideas to add to your collection or if they haven't been mentioned yet. : )
Mazin Saga Mutant Fighter
Shadow Dancer: Shinobi
Shinobi III
Vectorman 2
Road Rash III
Super Hang-On
Contra: Hard Corps
Toejam & Earl I and II
The Haunting
Shining Force
And finally, the only Genesis game I'm on the hunt for is Guantlet IV. I've been looking for more classic games that are highly replayable and with multiplayer, and this one just happens to support a multitap for up to 4 people.







