Yay! Glad you liked it
I like the idea of these competitions, they kind of give people a reason to actually create concept art. It's rare that I try making art, but this made me go Huh that guy wants concepts, why not?
For the future though, more time would be good. If you have work, school, family etc. it may get stressy with only 4(?) days.
I think I have some humblebundle keys as well, I have to check. You shouldn't do this for free games, but prizes are always fun