Nice project to support!! there you have some suggestions to consider: retro-style components (pixel art for 8bits, 16bits, arcade machines), layer support of graphic editors other than photoshop like photofiltre and gimp, isometric elements, backgrounds with water-color design, animations and some way of personalizing them (animated eyes, mouths, brows, different walk/kick/punch cycles, animations for weapons..)
I hope that your project gets funded and also that you gain great popularity among the independent community