The 6th Annual Vanilla Level Design Contest: Collaboration Hack is a compilation ROM hack of Super Mario World featuring all 84 entries of said contest as well as 4 switch palaces. The entries are organised into general themes on the overworld. The entrants were tasked to make the best level they can make in a given timeframe whilst not using any custom graphics or ASM, making for a varied experience throughout. It can be downloaded on SMW Central.
Darkman425 completes every exit, but also collects every single Dragon Coin and 3-Up Moon that are spread throughout the various levels. Please read the author's comments for more details.