Better than you'd think.
Story: The story is nothing special but at the same time it introduces some actually memorable characters and the about-as-classic-as-you-can-get villain Dr. Wily, bent on taking over the world with his army of robot masters. The story differs a bit for each of the three titles, but the substance is still the same, so I won't go into much detail here.
Gameplay: Mega man is a 2D side scroller in which you take the role of our famous "Blue Bomber", armed with just your mega buster as you attempt to stop Wily's robots from causing havoc on the planet. The game is somewhat non-linear, as you can choose to start from whichever level you prefer, as opposed to games like Mario where you can't choose to play one world before another.
In the first game, there are 6 robot masters (the robot masters are 8 in all subsequent games), also known as bosses: these are the evil guys and Wily's henchmen, and are fought at the end of a robot master's respective stage. They have one or more weapon (their AI and weaponry got more advanced only in later titles) that is particularly effective against Mega man. Upon defeating a robot master however, mega man acquires one of their weapons. Each robot master has a different weapon that has a different function, and may be more effective against certain types of enemies, as well as bosses. In fact, bosses have a weakness to a certain type of weapon. For example, in the first game Cut Man is weak to Guts Man's super-arm, that may take him out in 2 mere shots. Guts Man on the other hand is vulnerable to Bomb Man's weapon, and Bomb Man is vulnerable to Fire Man, and so on.
Upon defeating the 6 or 8 robot masters and finishing all of their stages you can finally get access to Wily's castle, his hideout from which he administrates all of his operations. This "final" level is usually divided into 3 or more levels, each of them having a boss that is even stronger than the robot masters (Yellow Devil anyone?), until you eventually get to a rematch against the robot masters one by one and finally against Wily himself in his famous Wily Machine (accompanied by the Wily Capsule in later titles). All around, Mega Man has some memorable boss fights, even though those in the first games aren't too complicated and often too easy, they were still revolutionary at the time.
Regarding the stages and a few more things, the stages are of course full of enemies and hazards, most of which can be killed. Upon killing an enemy, he has a chance of dropping several items, including healing reactors and ammunition for your special weapons or gadgets (Yeah there are gadgets too, although most of the time you only need them to climb over a very tall wall). Because of this, whenever you leave the position where the enemy was located, the enemy will show up there again if you return there, so you can refill if you are badly injured (This however does not work for some of the strongest enemies that simply remain dead). The stages are fairly well designed, with many enemies blocking your way and lots of platforms and jumping parts. On a related note, Mega Man willy simply take damage from most attacks, but if he falls into spikes, he will die instantly, so be on the lookout for them. Another worth mentioning thing is the sliding, which allows Mega man to crawl into narrow spaces and move faster than when walking. It is introduced in Mega Man 3.
Some people have reported slow downs when facing certain bosses, but when I played this in Gens (emulator) I didn't have any slow down. (maybe just a slight slowdown during the yellow devil boss fight but it was so slight it was basically unnoticeable). Again though, I'm pretty sure Gens is more powerful than a regular Genesis, but heh.
Graphics: The graphics have been updated from the NES version and look MUCH better. They are not nearly SNES-quality, but they're still 16 bit. Nothing wrong here.
Sounds: The sounds are too not nearly as advanced as the SNES' ones, but again are not too bad. They aren't quite as good as the graphics though. The music on the other hand contains remixes
Differences with the NES versions: For the fans of the classic NES games I'll list all (or most) of the differences Wily Wars has compared to the NES titles:
- The inclusion of an all-new game called Wily Tower with 3 new Robot Masters (that are more powerful than all of the others).
- Some of the bosses' AIs are slightly different, and most of the time the bosses are actually tougher. For example, Cut Man takes one third of the damage he took in the original Mega Man. Quick Man is slower in this game but it takes twice as much damage for him to die, and I actually think the Quick Man boss fight is A LOT harder than in the NES version.
- There is a slight delay in movements. The slight delay before moving in actuality is that Mega man moves of just one pixel and then after a just slightly noticeable amount of time he actually begins to walk. This is actually VERY useful for certain types of timed jumps with the disappearing blocks but is sometimes annoying when facing certain bosses. The slight only affects walking and not jumping or sliding.
That is all that there is to say I think. I found Wily Wars to be a good conversion of the classic titles, definitely worth getting as they even have some extras. In other words, they're the classic games, plus a new one, except better as they've been updated. However, Mega Man 7 and 8 are way better than these.