dropped the price on a number of their games, including the mobile version of Mega Man 2. While it may not be the best port, it's certainly a nice on-the-go fix ... yours for only $.99.
Of course, this sale is for a limited time only, so if this version of MM2 is something of interest to you, I'd advise you go ahead and make the purchase ASAP. Also of note, don't be fooled by the iPhone hype; Mega Man 2 is also compatible with the iPod Touch and iPad.
It's worth noting that Mega Man 2 "i" has received a fair amount of flack in the past, but the game is growing increasingly more playable thanks to numerous updates. A lot of improvements have been made since its launch a couple years back, mostly in the mechanics department. It's not a perfect port but like I said, it's a good quick Mega Man fix.
Full sale details and more eligible games available at Capcom Unity