There is more PF2 players on the forum because it's something more useful for PF2 users.
And Hungry Cat Picross players is a broader audience, young kids, girls and boys and also seniors
but they are less forum users.
About or datas, it's hard to summarize, there is a lot and it's divided on many supports.
It's something around 5000 players/day which can seem little given what other games do, but for a 2 guys studio it's really cool
For Hungry Cat Picross:
It's around 10000 players/day with pikes at 15000 on tuesday.
Picross' game sessions are shorter though, so in the end PF2 and Hungry Cat Picross are in the same range of revenues for Tuesday Quest.