level development was done by playing nes titles and taking notes on which characters they wished to include and where. rather than have each level feature just one group of enemies from the same game, they would instead act as a tribute to the system as a whole and feature a variety of them. during the course of development, smaller projects were also done in order to keep themselves motivated and meet financial obligations. by 2009, the first three levels of the game were completed and revealed at the san diego comic-con, playable with a nes controller as originally intended. with the game well-received, they resumed work, using feedback from the test to fix bugs and issues, and in 2010 presented the game at the following comic-con in a free-to-play arcade cabinet, with artwork made by jeff bandelin of newgrounds.