Capcom and Nintendo recently teamed up to announce Mega May, which will spend the whole month celebrating the Blue Bomber. Every Thursday will see a different Mega Man game joining the 3DS Virtual Console lineup, starting with Game Boy Color's Mega Man Xtreme, which is now available.
After that they're adding the Game Boy versions of Mega Man II and Mega Man III on May 8, the GB Mega Man IV on May 15, GB Mega Man V on May 22, and Mega Man Xtreme 2 (GBC) on May 29.
Capcom originally set it up for fans to vote on their favorite games last month. The Xtreme games are $4.99 each, and the Mega Man Game Boy games will be $3.99 each.