Note: This is quite old and by no means my best or most polished game!
Consider also checking out SD Powered Up, SuperDanny 2 and Mega Man Endless.

Humiliated by his defeat in Mega Man 5, Star Man is furious that his second chance to prove himself was ruined by Mega Man V for Gameboy using original bosses, so after years of training he sets out to defeat the Stardroids and prove that he is the greatest space robot ever created. Despite his training efforts, all Star Man has really learned is how to walk; other than that he functions exactly as he does in Mega Man 5. In order to attack you must create a shield while on the ground and then fire it while in the air. With practice this can be a surprisingly effective attack method, while also working good for defense.

Shortly after I started work on the original Gameboy-styled Star Man, I decided that it would be awesome to do it in NES style someday, mostly for the colored Stardroids and their levels. As the original Star Man progressed and was finished, it was a common complaint that the screen is too small, making for some blind jumps and limited room for attacking, so the enlarged screen of the NES (256x224 as opposed to 160x144) would also be a big improvement.
While not quite as true to NES as the original Star Man was to Gameboy, Star Man -Upgraded- is most definitely upgraded, bringing more life into the game with colored graphics and improving the game in many ways such as the larger screen size, built-in customizable gamepad support, revised bosses, a highscore list, play time given at the end of the game, a new hidden challenge and more.