Over the shoulder 3d view, ThirdPerson? RougueClone?.
Prefab dungeons (some outdoors) with a 'room by room' setup (notably, monsters cannot exit their rooms) and a 'get key to progress' type of puzzle system.
A built in LobbySystem? gives access to groups of up to four players to take on the game simultaneously.
A simplistic power gain system is complemented by a 'level up your pet by feeding it items' system, which allows additional customisation.
A good old basic 'whack monsters and get treasure' type game. But multiplayer. And 3d. It looked shiny as all getout on the DreamCast, but is showing its age now.