The back is done, but, as mentioned, it's pretty much like what you saw before, but a little bigger.
However, the front is also mostly done (except for the front vents). The utility arms are probably the least detailed part on L3-G0, "the plan" is to improve L3-G0 over time. Adding arms seemed like it'd take a while to figure out, without adding much. Eventually we'll probably have doors and other stuff, and maybe even utility arms, but the first goal is just to get him built! It's Lego, so we can update him later as needed.
The kittens have a different plan for L3-G0. They think he makes a nifty cat house or cat toy. Cats love boxes and I guess they decided his body is a box. The missing vent is apparently a perfect kitten door. (I confess to using the streamer to get him to pose for the camera, but the kittens were the ones that started climbing into, and over, the body. The also think the loose Lego bricks are great toys.)