There isn't much to critique on yet, but I see that you use different outline colours for different objects. I think that it's a very smart choice, as it leads the readers' eyes to the things in focus.
If I may suggest: use same colour outline for the rat and the thing he's interacting with. For example, in Loot (2), there is a scene where RPG Rat is trying to open the fridge. I think it'll look better if the fridge has black outlines too.
On another note, I wish the text were bigger. I have a lot of difficulty reading it, even on my laptop.
Good luck on your comic!