A claw-based inserter concept from when all machines had to stack vertically on top of each other in a clean and obvious way. This is probably the closest concept before we got to the final design.
A top-loading design in which each inserted had a crane-game-esque track that connected directly to conveyors and machines.
A more refined crane concept. It allowed for a few nice QoL features like scaling length, but was ultimately scrapped for various reasons.
A couple earlier versions of the overhead track. They proved to be too bulky and complex for the animations to fit actual throughput in game.
Techtonica - The Inserter
The Inserter was one of the most critical machines to get right for Techtonica, and we spent a lot of time sketching and prototyping various ideas to make sure that it both felt intuitive to use, but also fit into the grand scheme of a megafactory. Over the course of a playthrough, the player would construct and place hundreds, if not thousands of these Inserters, so the UX was extremely important. I made modular prototype assets for all of the designs that we wanted to test in game. We ended up going with a more classic Factorio-style design in the end, but I still like how some of the early concepts felt in smaller scale factories.