Assuming you're aware that it requires an online server when you buy it.
I recently bought LEGO Batman 3 since I love the LEGO games and enjoyed the previous two Batman games in the series. None of them have ever had an online component. LEGO Batman 3 has no online multiplayer, it only has single player and split screen co-op.
Guess what? It requires an online connection to some server somewhere. This isn't mentioned in the Steam page anywhere. If you can't connect to the server, you can't play the game.
I hadn't thought to check if it required an Internet connection to play because why the fuck should it?!! (And if I had checked, I almost certainly wouldn't have found out about it because none of the reviews mention that fact.)