i think tf2 surf was how i got into the whole movement-based game thing, as i'm sure many others did too! definitely appeals to people who like time trial / speedrun type of games as well.

i love that you don't have to be good at it, you can just play the easy maps and play them any way you want. also the skill ceiling is crazy high, so you could practice for years and still be able to improve (though towards the top it becomes fractions of fractions of seconds off your time).