Coldsnap is the third set of the Ice Age block. It was released ten years after Ice Age was released. It marked the longst time an expansion has been released after its predecessor. It supplanted Homelands as an Ice Age expansion.
The set included many of the elemnts of Ice Age such as cumulative upkeep and snow lands. It also introduced ripple and recover. Among the power cards of the set are Adarkar Valkyrie, White Shield Crusader, Commandeer, Controvert, Counterbalance, Rune Snag, Lightning Serpent, Ohran Viper and Scrying Sheets.
While the set did introduce some tournament quality cards and had a nice nostalgic feel, it had a very low power level. I think that the designers focused more on rewarding old school players with nostalgia rather than producing a game breaking set.