both games are visually awesome and stylish, a lot of atmosphere and ambience.
Onna = fighting system incomplete? seems so clunky n random.
Umbra = extremely slow on my Chrome, im running an Ivy Bridge i5 CPU with HD4400 graphics, runs other html5 games fine. it was too laggy to play.
regardless, i am impressed by your sense of style and ability to give it a very immersive ambience.
the other pixel art c2 title (besides Dungeon Buster & Kitsuni) i can think of that matches yours on that visual level, would be the sci fi game Space Expedition:
Either way, there are heaps of great content being made with c2, I think its time Scirra has a showcase section on their site, linking to a few games that is rotated or linking to a list that keeps on growing etc. C2 needs more examples besides Ubie Land on the website.