Possibilities to consider: all the major funding is going into new features, the new shadow world (Which I think is actually a world of past trauma), probably even some new areas, enemies, and in the far future: bosses. Ontop of all that also having expanded lore from happy heart hell. And let me remind everyone: This is one developer and their spouse, minor bugfixes are common, major updates take time, effort, love, and yes: money, big money.
If the dude arguing me would hear me out:
Think you can do better without any help from any outside sources, code built from the ground up, for animations, voice acting, plot, mechanics, supertough enemies, grunts, bosses, maps, collision, no collision, moving platforms that have a light to confirm you're on it, multiple game over scenes, transformations, effect statuses, like 100 different ways to struggle out of an enemies embrace, 50 of which if you don't get out in time adds a BROKEN status, dozens of sub areas in main areas, a cheat mode for the casual player that actually works in both making the game harder for someone or making it easier for a newbie, optional game overs from "staring" or being in the presence of something too long, a currency system, having to balance the currency system because of so many items and *ahem* services, one of the bosses literally requires $600(Ingame) in alcohol to get drunk enough to fight and attempt to steal her book and having to ONTOP of that program 2 different game over scenes?
I'd love to see you try %75 faster than the features in this game, meaning an update every day: You think you'd be able to handle that as a one man development team?
Of course all thats hypotheticals: Of course you couldn't. You couldn't surpass this game in terms of content entirely from scratch and thats just the truth. Doctor called in, he's saying he has some hard pills you need to swallow.