where to get some characters??

[dawg]

how do you get other characters like clayface, twoface, riddler or joker (not tropical)?

[markrevell]

The characters become available/unlocked as you play through all the Story levels, good-guys in the Batcave and baddies in Arkham Asylum and you can then purchase them at the Batcomputer terminal. You have to do the corresponding hero mission first before you can access the villain one. Once you've bought the character you can use them in Freeplay or wandering the hubs.

Hope this answers your question :)