I have been trying out lots of pixel editors in the last few months and I forgot that C3 had one.
It's actually really robust but there is one feature that needs to change in order to be consistent with other pixel editors. In fact, there are a lot of features in the pixel editor that are already in other high end editors.
It's the checkered background. Usually the checkered background indicates a pixel. It just looks a bit weird to not do it this way. It would be better to have the background like photoshop where it is grey or toggle-able black and not the checkered.
Having a pixel grid be toggle-able as well. This is of course different from the grid. I like having the grid be able to do larger grids like 16x16 or 32x32. This is good for tile-maps and is a main feature of pyxel edit. http://pyxeledit.com/
Having the pixel grid like pixaki would be great. Pixaki also has preset pallets which is really nice. https://rizer.co/pixaki/
Anyway, I think if you added these features C3 would have an in the box pixel editor that could compete with literally ever other editor on the market.