I imagine it's probably going to take a while to get a lot of that stuff (such as classicvania mode, rougelike mode, and boss revenge mode), and we may have to wait as long/longer than we've had to wait for all the content in Shovel Knight to drop. I imagine it'll all be worth the wait, but I do hope IGA isn't just stuck developing for this one game forever. That's kind of how I've felt with the Shovel Knight team, though it has all been pretty successful for them, so it'll be easier to fund their next outing (which is what I'm interested in seeing at this point).