Sorry dudes, the Mega Man Mega Buster gun replica is still in ThinkGeek's scheming stages. Full production of this beta version is not expected to hit shelves...and the arm-cannon-hungry hands of holiday shoppers...until December 2015. But in the interim, you can watch the video of the prototype in action and fantasize about what you'll do in 550 days when you are finally able to load up with solar energy.
The Mega Buster replica will include the full gamut of light and sound effects. When turned on, the cannon will play a power up sound and illuminate its power meter as it fills up. Once your arm is nestled inside and your brain prepared for action, trigger pulls will fire off energy blast sounds and the blaster's end will flash. A held trigger will produce continual, intensifying sound as the power meter fills, and then fire a supercharged shot upon release.
Cosplayers and video game diehards with forearms of 4.8" or less in diameter, your days of boulder destruction are upon you.