Bullet is a weenie dog with a drone that shoots for him, and he can ride it to evade fire. Doris is a musclegirl cyborg who uses dynamite instead of guns, with a charge mechanic for bigger blasts.
Teaser for the new caracters here: https://www.youtube.com/watch?v=5-eZkp0D5eM
But really, the best thing about this is that despite being a 4-player game with four characters, everyone can still play whoever they want. The biggest obstacle to having fun in old-school multiplayer, finally removed!