A downgrade after the previous Mega Man games
The main concept that Mega Man 4 had was to introduce us to the chraged Mega Buster. What was a great idea and later would become one of my main positives for a Mega Man game, but in their first try it made the game slow, and took too long for you to charge it. After Capcom perfecting the formula with Mega Man 3, in my opinion. And Mega Man 2 being a big step up from the original, and having amazing presentation/soundtrack. You cannot feel anything other then a bit disappointed in the 4th game of the series.
Mega Man 4 would be the 2nd to last game I would recommend in the original series, even after 8. Just ahead of the original one. The gameplay is the same, 8 bosses for you to fight and get their weapons that become a weakness for another boss. The ending is just bizarre and doesn't make much sense. But most Mega Man fans don't even care that much for the plot.