Just ran through this game. Took me less than an hour, so yea, super short. But a cool little game nonetheless. I enjoyed the style and soundtrack and though there was nothing at all I hadn't seen before, I am a sucker for classic Mega Man gameplay.
I thought the stage length was a pretty good compromise from the modern "checkpoint every five steps" approach and the much less forgiving games of yesteryear. The game did seem to actually get easier as it went along, though. I think they might have thought the later mechanics would throw people for a loop, but like I said, I've seen it all before. Perhaps I should have played Hard mode.
Is the sequel meatier and does it add anything new?
The sequel is just as short but it does add a few new gameplay elements such as horseback riding and Star Fox-ish level segments. Also you have different characters to choose from right at the beginning but I'm unsure if they change the game in any way. It's a fun game if you enjoyed the first. I thought it was more enjoyable overall. It's hard to really go wrong with the low price of these games.