The GameBoy formula is worked out yet again in the second GameBoy installation. However, this game is regarded by many as a step down for the series. I agree somewhat, but I enjoy it nonetheless.
A little bit of story is given in the manual; Dr. Wily has stolen a time machine from the Chrono's Institute, and Megaman tracks him down to recover it. But since there are yet again no story scenes, we see no mention of the time machine deal at all. We do find out through other sources that the robot called Quint that Megaman battles against is actually Megaman himself that Wily has captured in the future and brought back through time. However, this is not mentioned in the game itself. What we do know, is that Megaman battles against a slew of robot masters from MM2 and MM3.
Megaman can slide in this game, giving him quite an advantage now against the MM2 RMs. Rush is also here, with the same adapters from MM3. In this game, Megaman must earn the Rush Coil part as well as the others.
The graphics have slid down a notch. The robot masters in particular look puny compared to Megaman. It looks almost as if there was an attempt to shrink down the sprites, but partway through they decided to just go with the regular sprites and didn't bother to take out the ones they shrunk. The end result is very bizzare, seeing larger robots like Woodman and Needleman looking dwarfish next to Megaman. Plus, the soundtrack took a dive. The cool RM themes have been replaced by very tinny, high pitched squeals.
This is also a very easy game, perhaps the easiest in the series. That could be in part due to you being able to get Rush's adapters so early, you can fly right over any hazard with ease using Rush Jet or Rush Marine.
One more thing worth mentioning is that this game, in spite of its downsides, along with Dr. Wily's Revenge were rereleased as part of Nintendo's "Player's Choice" series for GameBoy (which rereleases games that did exceptionally well and are still in high demand).
