Pocket Mario
A fangame most people were waiting for in the early days of static engines. Run by Klobber and Retriever II, it looked, sounded and tasted great up to the point of its first demo release.
The demo release caused many people to dislike it out of over-hype or the fact that most PCs couldn't run it properly due to a faulty and resource-intensive engine. An earlier version would tend to close itself without warning, causing frustration for many. Raining goombas were common.
At one time the game was stolen by King Piranha Plant, an act which caused its creators much distress.
The game is currently still in development, with a re-worked demo slated but not yet released. However, Retriever II has released a partial open-source of the old engine's main movement.