That sounds awfully like a Mark Hamil Joker (which is of course excellent) but I thought he had retired from that now. If its someone else they are very similar.
It is Mark Hamill He stopped doing the Joker for a bit hence why he didn't do him for Batman origins and Troy Barker did it instead, but he came back for Arkham knight and the animated stuff with the killing joke being the first big one he came back to.
As for this i dunno there is nothing to show what it is, I took a look on shop.to ect and it's up at full price so i assumed it was a full game but i'm hearing it's more of just a experience not an actual game so why it's being charged as a game i don't know maybe it's just place holders for now, at least i hope so it wont look good for Sony if experiences are being charged at full game prices.