well, the ability to save the game is needed before everything else, obviously.
next, i'd say, a controller support: even though it is trivial to map controls through the Steam Input (by adding a non-steam game to the library), i don't think it can enable this precise acceleration/deceleration that gradual pressing of the trigger buttons gives you with proper controller support.
also, an option for the free camera during cargo loading would be nice. which is to unlink the movement of the camera from the movements of the tower/arm, and set the position of the camera manually. because with this view from up-top (and with weird collision (the stuff freely going through the cargo bay walls while loading)) it is not always clear where exactly does it land. consequently, the whole process is tedious and irritating, at least when you have to deal not with some odd-shaped junk (just shove it in there and keep rolling), but with square/rectangular cargo that needs to be neatly stacked.
i'd even say that if a project gains traction (no pun intended), it makes sense to give a casual player an option to fix (at lest these rectangular ones) cargo in place, kind of like in Mud/Snowrunner with logs, or heck, even in Death Stranding with containers. maybe not from the get-go, but as a purchasable upgrade? although, without it present from the start a lot of people will abandon the game after the first half an hour, so maybe as an easier difficulty level?
also an option - additional cargo spaces. for example, while delivering an almost full cargo hold i came across an expensive ahh i-beam, so i chugged it between a cargo hold and a tower. neat, but what about also "tying" some to the sides of the armor, like we sometimes see in those ww2 photos with random ahh logs? that would be a nice upgrade option.
and a little quality-of-life thing: while changing game's volume in the OS's mixer is always an option, having an in-game volume settings (general, engine, music) would be much more convenient.
all-in-all, game's scratching a very particular itch, so it'll be able to find a loyal, albeit niche, fanbase. but also, even though it's rather simple in terms of looks, it is looking cute and, most importantly, coherent, like a proper game (well, not like - it is one), which opens the gates of a mainstream appeal. so given a proper execution, i fully believe that it can not only be a little gem that only a few know about, but a rather recognizable name generally, with console releases and all that jazz. if possible, do not abandon the project, give it some more love and care, and it could be the beginning of something beautiful. and in the world of safe bland re-reused corporate slop we do need more beautiful. good luck with the project.