Mega Man Zero 2/Allusions

References to Mega Man Zero 1
In Mega Man Zero 1 each one of the first six stages was the setting for two missions, hece summing up to 12 missions (followed by the four final missions). Mega Man Zero 2 takes inspiration from that: each one of the first five stages has a parallel in one of the following stages (with one exception). Furthermore, each pair of stages corresponds to a stage in Mega Man Zero 1.