All PvP games can be gambling if you bet on it. You confused me a bit, I`m thinking about PvP gambling games for bitcoin. Only poker is coming to my mind, and there is no other. This fishbitfish.com is not a real PvP game, it`s many players vs many players, and if you have a strong group you can easily manipulate with the game I think, I never won anything there.
Poker is a good game, you can choose you game there, there is more different games. Other games I don`t know, and I tried a lot of gambling games for bitcoins.
fishbitfish doesn't require "many players" or a "strong group". It's all about buying out, and having a larger bankroll (and having the blocks work in your favor.)
If your transaction doesn't confirm... there goes your total. If you run out of funds... there goes your bankroll. If you wait too long and have to pay a huge fee... there goes your bankroll. It's an interesting game, but I haven't used it in many months - so I can't vouch for its security anymore. I used to play on it, though, and back then, I generated quite a profit.