Nice game, with stylish visuals and a fun concept. 

Controls need a bit of polish, for example when I click to drag and drop an item, when it is in front of a box that gives a body part, the box also gets clicked (a simple fix that wouldn't involve having to mess with raycast results would be to move the boxes up by a bit so that the body parts don't fall on the ground right in front of the boxes, and the chance of clicking a body part together with a box is lower), plus also the cleaver doesn't feel right (oftentimes I find it removing the whole body entirely instead of the head or arm or leg I want to remove, which is tedious as it completely erases the progress on the monster you are creating). 

I feel like the "building" of the monster doesn't really fit well with the jam's theme, but the theme is optional, so that's besides the point of the feedback I can give you.

Overall, the game seems fun, and polishing the controls a bit would make for a nice pick and play game, on mobile specifically, so good job to the team :D

The visual style is very good! Everything looks polished. I just didn't like that the body parts appear randomly, sometimes you have to click on the boxes a bunch of times. I think if you add a selection of parts and a little tutorial it would make a good game!