I believe that many people forget about games that began as a small project on sites such as NewGrounds and even Flash websites, only to recall them all in the future when they go down memory lane in search of nostalgia. Similar to previous games like Friday Night Funkin, which began as a little project on NewGrounds but subsequently exploded owing to the flood of community-created content, it just seems strange that Rhythm Doctor did not receive as much or anywhere as close as the recognition they did.
It's a game that has been under development for the past decade. That's been going on for 11 years, and it's technically not done, since I'm sure they still have more stuff they want to incorporate down the road, but with a game this far along, you'd kind of want to expect a full release soon at the very least.