Thanks for giving it a go. It is steadily getting there. I have an update in progress that has greatly improved building placement. Once that is available (on itch) I will also do a demo vid on YouTube. However, I want to get the save/load game functionality done first, as that will also help with testing the game.
As I pointed out in the description (on the game page), a lot of buttons do nothing at the moment. Decommission is one of them, as it will need the corresponding additions to the droid state machine. After placing a building, all you need to do is use the building menu to assign an idle droid to build it, or use a droid menu and assign it to Build instead of doing something else.
I am also dependent on further development of the Godot Engine itself (I do not have the experience to help with this, unfortunately). Once the droids start doing something, the behaviour can go wonky because the navigation server still needs a lot of dev effort to improve the behaviour of navigation agents (the droids in this case).
I totally agree that assigning multiple units to a task will be a good thing to implement, but that is a long way down the list of things that the game needs... However, using the droid barracks menu for multiple unit selection is a great idea. I hadn't considered doing it that way. Getting good feedback like this is why I joined this jam!
By the way, to make Full Screen stick: make sure you have a profile created, then after choosing Full Screen, you need click Save Changes to save your preferences. Maybe I should disable the preferences until at least one profile is created.