To enter, vote for Braid on the wishlist (bonus points for leaving a positive comment there) and post here that you've done so.
SimCity 2000 will be given away, not on a particular date, but when Braid reaches 400 votes on the wishlist.
As of the creation of this topic, the votes stand at 276.
♬ Downstream - Shira Kammen
Check out my other giveaways:
Vote for Aquaria, win Deponia!
Vote for Bastion, win Lands Of Lore 1+2!
Vote for Cave Story, win Primordia!
Vote for Limbo, win Sid Meier's Alpha Centauri!
Vote for Super Meat Boy, win Ultima Underworld 1+2!
Vote for Unepic, win Resonance!
Vote for Vessel, win Gemini Rue!
Vote for VVVVVV, win Wing Commander 1+2!
Vote for World Of Goo, win Theme Hospital!
Aquaria - Bastion - Cave Story - Limbo - Super Meat Boy - Unepic - Vessel - VVVVVV - World Of Goo