Nice Progression, I kinda like this sprite version you did:
(albeit a c64 downgrade of your avatar)but I am not sure if that'd work 3 colours is your sprite colour limit? 4 i guess if you include the alpha channel, unless you can do some sprite dividing wizardry like the NES? where you can potentially break it down into 8x8 chunks, (which is detrimental to the sprite quantity limitations, but allows for interesting colour combinations) no? haven't really researched C64 specs, and haven't read enough to be sure.
but I've noticed in the latest screen shots contain 4 colours on the sprite, 1:Grey 2:brown 3:Green 4:pink/flesh.
and I am guessing filling out the 16x24 space a bit more will make animations more difficult to do?
(featuring 70s afro jumpsuit man)and Is your adventurer meant to be stereotypical fedora wearing adventure machine/adventurer ala Indiana Jones? or atypical kid wandering into danger?
here's me messing around:

I agree with Ptoing's comment on pushing the sprites readability on different BGs, especially with the similar palette, he does blend into the BG quite alot as is.
interested to see where you keep pushing this.