I really like seeing rpg monsters. Like monsters from the final fantasy series or dark fantasy monsters based off D&D. But environments are also good to see. I prefer pixel art.
oh, god i'd love to see way more puzzle game asset packs made by people. let alone just ones in the style of tetris, which is a bit low in number for me to find so far.
its the interface, and like the buttons and whatnot. that and theres tetris clones that have slight differences. i think it would just simply be helpful to have more of those assets out there by people
the 2d destructive could be done easily. for instance the mana seed collection has a town ruins pack and it matches up with the iconic town set. through eventing you could have it set up to work just like a bomb wall in a zelda game. just do it for each section of the desired structure.
Demand can be very variable. I am also an artist, I wonder what is wanted. However, this is something I cannot understand. So I've left it mostly to my imagination. When I understand this, I plan to work according to demand.