The game's interface is fluid as a snowflake that melts before you can show anyone: Simply click the mouse to skate and move the mouse to adjust the direction that your skater moves. This results in a really gentle adjustment that allows you to lace beautiful patterns all around. While you're sinking beasts into the lake, you can also pick up treats like ice cream and letters that spell "BONUS" which gives you points. Elegant and pristine with very nice pixel art filling out the sides.
Thin Ice is an enjoyable concept executed in classic Nitrome fashion, but it fails to provide an experience without a few minor kinks. In this case, the speed with which your trail recedes is equal to the speed of your skater. I guess the designer thought that making the two speeds equal would create balance, but it actually creates some frustration. Often I found myself chasing the trail in order to close a circle, something that might easily be tweaked by adjusting a variable in the code. Likewise, the physics feedback from colliding with a monster could be tuned down.
Overall, this is another fantastic experiment gone mostly right.
As noted in the comments, Thin Ice is a game with roots in another game of the same name released in 1986 by Mattel Electronics for the Intellivision. The gameplay mechanic of creating loops around enemies and objects dates back to the arcade game Quantum by Atari, from 1982. Notable Flash games more recently that employ a similar mechanic include gameLab's Loop and Ferry Halim's Floats.