Although I grew up playing the NES, I've never played any of the Mega Man games released for it (I played Mega Man X of the Super NES albeit for only a quick moment). Some years back, I came across this collection at a GameStop with the case & manual intact & didn't buy it due to lack of funds-& regret not getting it at the time after later finding out they sold it.
Now, I finally have this in my hands. You'll be getting 10 Mega Man games- although I got it mainly to play the 6 NES games. Mega Man 7, which was originally released for the Super NES is a decent game too, but Mega Man 8 (based on the PSOne release) may have to grow on me. The 2 games that needs to be unlock (the Mega Man Power Battle & Power Fighters games) are OK. They're nice additions, but not essential.
There are some differences between the games in this & their original releases. For one, when you finish a stage or lose all your lives, it automatically saves, getting rid of the need for passwords though they're still present in Mega Man 2-7 if you want to use them (the 1st & 8th Mega Man games didn't have passwords to begin with.) Plus you can set up the difficulty level (easy & normal) for all but Mega Man 8. Another interesting feature is Navi Mode which has in-game hints, remixed music & updated in-game menu. Flicker & slowdown is also greatly reduced for the 6 NES games-if you ever played the NES, you'll know what I'm talking about.
As you play the 8 games in this collection, you can also unlock features. Besides the previously mentioned Mega Man Power games, you can also unlock artwork, some of the game music & the pilot episode of the Ruby-Spears Mega Man series. I was slightly disappointed that you couldn't unlock the soundtracks of the games in this collection. While playing them, I realize how great the music is.
Although I can't really add anything else that's already been said by the previous reviewers, I will said this- contemporary gamers (those who only play current generation games) may get frustrated trying to play these games. But this collection is a dream come true for those of us who grew up playing the NES or 2-D plat formers.