Art style on Megaman Cartidges

The Megaman everyone knows is the boy robot seen in all of the games:

What most people don't realize is that Megaman is originally depicted on the first two cartridges as a full grown man, not a little boy:

 What's more, in both of those original game covers Megaman is holding a gun, not firing from his built-in arm cannon.


It's not until Megaman 3 comes out that we see his iconic childlike appearance and trademark weapon appear: