Built by three people over the course of ten years, ABA deserves your attention. Self-described as The Ultimate Tribute to the NES, I'd be hard pressed to find a game more elaborate and well executed - Even the fantastic Super Mario Crossover loses it's lustre after playing ABA. For Comic Con, the team whipped together a fake arcade cabinet that was a huge success, it's a shame that the game is not available as a NES rom - that would truly have been amazing.
It may seem that I am gushing heavily on this but it's just that good. Having lived through that era and played everything on display within the game, I just couldn't put it down - or stop laughing for that matter. The website allows you to donate funds to the devs and for your hard-earned cash, you get a downloadable version of Aboboy's Little Adventure, a game that will only be available through the site, via donation.