Very good game! found myself replaying it to try new setups, definitely a good concept that could be fleshed out, some minor upgrades could be allowing players to choose what the filters filter out (things like allowing only liquids, allowing only dust, or even allowing only iron for example.) And to keep the metal mixing system, maybe a way to slowly let liquids through a block, to allow them time to gather and mix? I always would just make a 1x1 bottleneck so they could mix, but a block to do this would be amazing! More metals, alloys, types of dust, and even planets would help expand the game! Very nice work here!
Edit: Also I can see some big performance issues throughout, especially in the upgrade menu! some optimization of that would be nice!