One of my all-time favorite reader comics was Matt. C's #205432 ("Magenta Kong"). It was one of the many great reader comics on 2.6: A Roadblock. Since then, Matt. C has done the unthinkable: he turned Magenta Kong into an actual Flash-based game. It's built from entirely scratch in ActionScript without a single ROM hack in sight.
Move Magenta along platforms and ladders with the cursor keys or WASD and use either Ctrl key or K to jump. Press 2 at any time to toggle sounds on/off and press P at any time to pause the game (the game music will be muted during pause).
Be sure to click on the game applet to give it focus or it will ignore your keystrokes.
Matt explained how he put it together:
I created Magenta Kong by first playing the original arcade game over and over until I had a very thorough understanding of the game's logic, the sprites I needed to redraw and the audio I needed to rip. I then recorded bits of gameplay as videos and stepped through them frame by frame to find out exactly, to the frame, how and when things took place.
Once I knew how it all worked, it was a matter of pushing it all into the game loop and testing it. A lot.