I tried to enter that on PCEA version from Steam and got an error message saying I wasn't eligible to play in it.
As a test I tried to enter it on the flash version and was able to enter it.I then played it on the PCEA version.
So if anyone is trying to enter it on PCEA and probably mobile as well and getting that error message just go to the flash site enter it there and then you can play it on which ever version you wish.