The one addition made to the game that isn't optional is its use of autosave in between each level completed. Essentially, this replaces the old password system used to save your progress in between bosses--so you wouldn't have to go back to play Quick Man's mind-achingly irritating stage over and over again. (Don't lie. You know you hated it.) Frankly, it saves plenty of time and effort. And, hey, you can always go back to just start a new game if you really feel like schooling Crash Man in three hits with the old air shooter over and over again.
But what would a classic gaming collection be without a bevy of extras? Though Mega Man Anniversary Collection isn't rife with unlockables, there are more than enough for any Mega Man freak to eat up. Aside from plenty of production art and remixed audio tracks, Anniversary Collection also features two arcade Mega Man fighters, only one of which ever saw any sort of release in the US. These games are Mega Man The Power Battles and Mega Man The Power Fighters. In these games, you basically just go through a bunch of boss fights against some of the more memorable robotic villains from the Mega Man lexicon. They're pretty light on gameplay or lasting value, but they're certainly worth checking out. The PS2 and GameCube versions both present platform-exclusive extras as well. On the PS2, you are treated to a full episode of the Mega Man animated series, while GameCube players get several producer interviews. Of the two, the producer interviews are definitely more interesting, but ultimately, it's a fairly even mix between the two.
The few mechanical additions made to the older Mega Man titles are in no way problematic. In fact, they are extremely useful.
Aside from these platform-specific extras and the lack of in-game remixed audio tracks on the GameCube version, the two iterations of Mega Man Anniversary Collection are almost identically playable. Control differences are practically nil, though one slight irritation on the GameCube controller is that its control scheme assigns the shoot button to the A button and jump to B. While a reversal of this formula seems like it would have been a more natural fit, this is a minor thing, and it really doesn't take any time to get used to the GameCube controls at all. Obviously, when it comes to visuals, neither version of the game really looks any different from the other--and if it did, then there would be something seriously wrong. When it comes right down to it, these are really, really old games that were--for the most part--designed for ancient hardware. If you have a problem with playing games that feature crusty, old sprites and very little in the way of visual detail, then Anniversary Collection isn't going to cut it for you.
However, if you don't mind outdated graphics and have any interest in Mega Man whatsoever, then there isn't a single reason not to pick up Mega Man Anniversary collection. This is simply one of the richest, most well-put-together classic compilations ever made, and it manages to not only refrain from sacrificing key elements of gameplay for the sake of making the hardware transition process easier but also makes improvements that are not only great but practically seem like common sense. Not to mention all of the neat unlockables that are sure to please any longtime fans of the Blue Bomber and his many adventures. And on top of all of that, you can't forget the fact that you're getting 10 games for the price of your average budget title. To be quite blunt, if you profess to be a proponent of classic gaming, you would be doing yourself a grave disservice by passing up Mega Man Anniversary Collection.