Your friend needs to explain what the goal of this game is up front! As soon as I saw the video I got the mechanic immediately--but had no idea what sort of scoring system was involved. Normal tetris scoring doesn't seem to apply, because you can't clear lines. It looks to me like this is a co-op game, which was not immediately clear. If I'm correct, you want to last as many bricks/as long a time as possible.
You need to state very clearly that it's co-op and the goal is to stay alive for as many blocks as possible.
I'm pretty sure its non-cooperative. If you look at 1:00, you see an instance where one player is told 'you lose' and the other 'you win'; so it seems to be zero sum.
The object seems to be that the player controlling the white blocks must prevent the white blocks reaching their side of the screen; and vicea-versa.
I find it hard to think through the strategic implications, without an android handset to play on, but it seems pretty elegant - you'd want to fill in enemy space where it is least likely to help your enemy.
So, if your enemy had almost reached the top of their screen, with one 'tower', you'd put blocks anywhere but into that tower. But that 'tower' is a large volume of empty space for you, crying out for you to put your tetrominoes into.
Game looks like its got some pretty interesting tensions.
