Version 1.1
Version 1.15
Version 1.18
Version 1.2
Version 1.3 (The big engine change)
Version 1.4
Version 1.5 (Coming soon…)
Version 1.6
Released
Unreleased
Two more major updates. The content from the previous roadmap still applies, just the timing is (obviously) different. Costumes are likely with the first update. CM2 will be its own update.
WHEN!?
VS Mode (Local/Online)
Chaos Mode (Local/Online)
Some clarifications from Question:
Yes. Split screen.
Double miriams.
The co-op mode is not a playthough of the regular game.
No crossplay, if that's what you're asking.
Estimated/hoped for November sometime.