Within the mid section of our project, week 3 focused upon the development & research of constructing the tower units & enemy concepts. The concepts developed within week 2 have been used as a layout for the towers & enemies to be reiterated into a voxel style tower. So far, the tower units have been constructed, each with its own 3 individual upgrade appearance. The remaining enemy characters are currently in development alongside the additional western book character.
Here is the individual tower upgrades for the totem book tower, separated. 
The corresponding book towers following their upgrades 
The starting level appearance of the barrel launcher tower
The Tower units created for the western tower defense, Barrel launcher, pillar tower, & gunslinger, each have their own individual upgrade appearance & ammo. Animating the towers would need to mimic the recoil & idle movement of the towers.
Game Design Year 2 Group WordPress 