Got a nice, long play session in today, mixing healthy doses of side-missions and story quests. Most notably the Penguin's museum. I particularly liked the macabre displays narrated by the Penguin: mostly grim warnings to those who would betray him, but also a few designed to hold future prisoners (Batman, Bruce Wayne, and the Joker among them). The rest of the level is fairly standard design-wise: a couple of action arenas, a couple of stealth areas, a big guy or two to fight (one with a hammer, just as in the Joker area) and a simple boss fight. It's all fun to play, but structurally formulaic.