Board Game Arena

Rive is in alpha.
boardgamearena.com/reviewer?game=rive
This is the first time Rive, a territory game, has been made available anywhere with an actual membership, so I can't speak to the gameplay. But the architecture is pretty crazy. You can completely wipe out your opponent, then they can come back and completely wipe you out, and you can come back and win. Rive is a finite game of course, but the churn rate is massive. Hence the tiny board.

Who should I contact to be able to help testing on this Alpha game?

I invited you to the Rive playtest group. You should be good to go. You can challenge me if you like.