April 22nd was previously Mega Man Zero Collection’s release date in Japan. North America was scheduled to get the game in the summer. The new release date for Japan is “TBD”. It’s unclear if the delay in Japan will affect the North American version since “summer” is a few months after April.
Mega Man Zero Collection contains all four Mega Man Zero games on one Nintendo DS cart. Retail product sheets listed extra features such as collection mode and easy scenario mode.