Early Access for "Crawl" just came out - now there's an interesting multiplayer mode, let the other players play the bad guys! There's that PvP thing again!
EDIT: For me, being involved with the early stage of a games development is very exciting. Being able to spurt out all you're fantasies in the hope of being heard and hopefully seeing them bring about a game you will love is a great feeling. That said, it dosn't matter what you think is cool or "right" for the game if you don't have a general understanding of where the developers are coming from and what they hope to achive. Personally I am comming at this game from the perspective of a huge Diablo 2 fan and more recently Dark Souls - so I imagine simple but robust leveling, extensive replayability, randomly generate dungeons, a hardcore mode and on top of that tough tactical gameplay based around stamina and timing. And smashing sh*& up and feeling awsome is all a part of that - but there is a thin line between giving the players the ability to feel awsome and making them earn it. I guess this is where my question comes in: Who is your target audience, and what is the core experience you want to give players from this game?