In a conventional sliding block puzzle game featuring a protagonist (by which I mean Repton, Boulder Dash, and Kurushi; I couldn’t come up with any more in the time it took to write this blog article, but maybe elements of Zelda and Tomb Raider count) there is a degree of identity between the player and the player character. Even if the character is a green bipedal lizard wearing a t-shirt and jeans.
Repton
The player moves the character, the character moves the blocks (or avoids them, in the case of Kurushi). The player feels kinaesthetically involved. It would be fair to say that in Repton, the player is Repton the protagonist (thanks Wikipedia for telling me the name of the protagonist!).
In Floe, the player / protagonist is not so coupled. The blocks move, but Flo does not move them. The blocks move by a mysterious force; at least, it probably seems mysterious to Flo. The way Flo moves is slightly indirect too. The player causes a pulsating target to appear, that Flo clearly finds fascinating and feels compelled to move towards it whenever it appears. Even if she can’t.
90% of the mass of the floe is beneath the water. And yet the player can tilt it. About a point very near the surface. The player causes psycho-kinetic delusions in infant polar bears.
The player is god.
Otterly 
Okay, not a very detailed article, a lot of obvious here.
I found a more detailed article, including the actual psychology of avatars. Here
Thanks Lance, that is an interesting article. My friend DRJ was being somewhat humorous.
I myself spend a lot of time in Second Life, and I’m very aware of the complex player/avatar relationships. It’s interesting that, during Floe’s extensive playtesting, people would say “Oh, the bear went there!” or “She got squashed!” and not “I got squashed!” We make use of this in the way we present the game. We say “a little bear needs your help,” stressing that you have a helping relationship with Flo, and are not meant to be her.
A much earlier piece on the subject of the relationship between the player, the protagonist, and the narrator (an important character in text adventure games, typically absent in graphical games) is Graham Nelson’s A triangle of identities from 1996.
On the subject of ice floes, David’s quite right that the tipping point is a bit too high to be realistic. I’m afraid it’s just one of many concessions that realism has had to make to gameplay. One very rarely finds coloured ice blocks in the polar regions either.
Some videos: Antarctic sea ice and a stranded dog.
Yeah, but only my article mentions a green lizard.
Seriously, I never suspected that my humorous intent would got unnoticed.
David, games and green lizards are SRS BSNS.