Tremorgames is a site created by a guy called tremor ( steam ).
In the site you got to register and start playing achivement games.
You get points by playing them, as much as points/coins you get as much chance you get to buy a good game for steam/desura.
Shop link:
Click meIt's impossible to buy awesome games therw with coins, since you need a life to get points that can make you buy a good game. Just buy a normal game.
Nothing is scam or phishi there.
And shell about desura games, desura is another gaming community like STEAM where you can buy, play games, chat with friends , add friends etc
More information here:
www.desura.com, desura games can be only actived there.
Tremorgames is not an awesome site or something. I suggest you to get inside the trading world, like darkness said start trading. If you need tips, just hit me up on steam!