It only takes me a couple of days to write up a draft of a game I think is playable. The three games I consider "done" from a design standpoint (Necropolis, Haunted and Raven's Hollow) each only took about half-a-dozen or so play-testing sessions with the biggest revisions happening after the first one or two.
Getting a game ready for production is what I'm struggling with there. There's a whole world of art and layout there that I know nothing about. I have a partner I'm working with there but she's also learning a lot of it as she goes, so it's slow going.
RE: AprilTTRPGMaker Day 4: Describe Your Work.