Alternatively "Return target snow creature from your graveyard to the battlefield with a +1/+1 counter on it." Which is better?

At that cost you probably meant -1/-1 counter anyway.

Snow creatures exist. This two mana reanimation still hits 10/10s and flying 6/4s in this very set and you get a bonus rather than the usual "lose life equal to its mana cost"?

Nope.

This set does not use -1/-1 counters.

I forgot that in modern times reanimation isn't cheap, even when restricted. Perhaps 5 () should be the cost?

You usually get any type of creature with one or two +1/+1 counters at five e. g. for Fearsome Awakening.

So a converted mana cost of four is closer for this card that gets you a counter, but cannot be used on nonsnow anyway.

I think, the better design is to reanimate any target creature, but get a counter or two for snow creatures.