I've been playing the Smash demo and played A LOT of Mega Man because he is one character I'm planing to main. I want to share what I've tested so far and my impressions (some of this has probably been said already).
Mega is a character of zoning and pressure. You'll want to be medium range from your opponents all the time. You have to keep your distance, poke, then approach o pivot ftilt away to catch your opponent's approach/roll/etc. You don't need to roll much just pivot ftilt or sideB. Mega Man is a great character, but very different from the rest of the cast.
Pellet game.
Jab/Filt is an excellent poking tool. You'll want to Pivot Ftilt a lot with Mega... Is too good.
If you feel you are too close to your opponent, Pivot Ftilt away or jump away (Nair, jab and Ftilit are part of the same pellet combo. You can jump away if you feel you're in danger). If a pellet damages the opponet and you are close enough,
you can stop the jab combo and buffer a grab/running grab. The pellet hitstun is enough for you to approach with the grab/running grab.
It's kind of tricky to learn at first and you should learn the grab distance to prevent openings. Pellets are an excellent way to defend yourself from enemy's proyectiles, you can destroy things like Mario's Fireballs, Links boomerang and arrows, Pikachu's thundershock, and Villager's rocket thing.
Metal Blading.
Metal blade is an excellent tool to punish, gimp and disturb your opponent. You can't throw a new MB if there is one on the screen. The Metal Blade lasts around 1.3 seconds in the air before disappearing, after that you can throw a new one... If you learn to time it well, you can keep spamming MB.
You usually use MB when you are not close enough or
when your opponent is about to land to force them to air dogde near ground or disturb the teching (if the MB hits even better). After a dash attack or Dtilt your opponent falls in an arch to the ground, that is a good moment to throw a MB in front of you... or if you read a jump diagonally upwards.
Crash Bomber.
You'll prefer to throw MBs, but you can CB after a MB or if you cant throw MBs because one is stuck somewhere on the stage, etc.
Its a got move to pivot and keep your distance. You can plant one on the edge when you are recovering to force your opponent to be careful with his edgeguard.
Leaf Shield.
IMO not very useful. Is good to rack damage while grabbing. After 3.5 seconds the shield disappear if you dont throw it. If you position yourself over the edge, the shield covers it so if somebody is going to grab the edge could be hit by a leaf instead (not a big deal, they'll grab the edge after that anyways).
The shield have a lot of startup, personally I dont like the move. Maybe the custom ones are better in some way.
Grabs.
DThrow is good for follow ups. At low percentages you can:
- dthrow to Fair (if your opponent keeps air dodging after dthrow, Nair instead and the pellets will hit).
- dthrow to Bair (its tricky to do but is a nice 17%... Buffer back during the throw and after Mega puts his foot on the ground, jump and attack the opponent).
At higher percentages you can throw a MB diagonally upwards to chase the enemy after a dthrow.
Up throw is good if you want to try a kill with Uair.
At high percentages, if you Fthrow your opponent away of the stage (near the edge) you can throw a MB diagonally upwards to disturb your enemie's second jump.
Bthrow deals a sweet 11%, follow it with a MB to keep preassure before you approach.
Edguarding and edgeplay.
MB to gimp, except diagonally downwards (you could help them recover instead).
Dtilt sticks to the edge and if you hit with the last part of the move, you send your opponent in a 40º arc.
Even dash attack is good to edgeguard.
Utilt is good for edgeguards and is an excellent killing move. Plus if you use it to edguard you'll fall and grab the edge skipping the terrible ending lag of the move. The opponent wont be able to punish you if you miss.
When you trump someone off the edge, press down > jump > bair. Bair is super quick and excellent to kill at higher percentages.
If you grab the edge and someone is waiting you on stage, you can drop the edge > jump > Fair onto the stage.
You can drop the edge > jump > walljump > bair too. I've only tested this on Omega Battlefield because of obvious reasons.
Dair is really good to spike, but is tricky to land the hit.
Fair is great after grab releases near the edge, to chase the opponent off stage.
Both MB and CB can be used to prevent gimps when you are coming back to stage.
Fsmash's range is really good for edgeguarding.
Upsmash is very good for edgeguarding too and racks good damage if chained at low percentages.
Rush Coil.
Use it not only to recover.
Rush is an excellent way to escape if you leave yourself open. Like when you Dtilt or Dash Attack and you opponent shields... When the move ends behind the enemy you'll want to rush coil away.
Rush Cancel is an interesting find by VGBootCamp's guys. I've been able to escape things like jabs, dthrows and multihits moves that could kill me in the moment.
When you get caught in a move like Link's Spin Attack in the air, spam UpB to Rush Coil out of it.
Note: Pivot = Turnaround Cancel (some people call it like that)... And sorry for the WallOfText xD