First of all, the music amazing. That drew me in right away and kept me playing :)
I agree with the feedback below about menus closing each other. It would be nice if there were hotkeys for opening the windows but that would be a nice bonus, not mandatory.
The biggest issue for me is the progression of the game. The most effective way to progress is to use scrap -> minerals -> prestige. This gets particularly effective when you prestiged some times, unlocked some upgrades and amassed knowledge and connections. After the early stage you can prestige after 1 or 2 clicks and rinse and repeat, and that lets you grow very quickly and effectively especially in comparison to trying to get to your previous progress.
I guess this is why many idle games let you prestige only when you come close to your previous progress and surpassed it at least a bit.
the other thing that bothered me a bit was that only the latest business/resource is relevant. there is no reason to invest in minerals when u have tech or in robots when you have meds.
so, as mentioned, it might be nice to give upgrades for lower resources to let them stay relevant.
OR and that would be more fitting with the existing system and presentation of the game, it would be cool to expand the regions-menu.
an idea would be to divide sectors into subsectors, and possibly even add trade routes. and different sectors could focus on specific resources. so lets say the sector alpha-centauri focuses on minerals and scrap and each sector boost your whole income by a bit, but your scrap and minerals income by quite a bit. and upon aquiring all subsectors you get an effect of monopoly that exponentially increases the income of said resources. this way low tech resources could stay relevant, surpass higher tech in the mid game and late game be overshadowed again. also it would fit with the whole business vibe
it might be also fun to allow non-linear progression of sectors, so you could expand into multiple sectors, and it is not so easy to build a monopoly in a sector/resource.
trade routes could be something that you unlock when you have different sectors and establish connections in between.
Lastly it might be nice to unlock permanent upgrades not only with prestiging, and tau coins, but also with certain progresses of the game. so either aquiring a full sector might stay permanent, or at certain milestones, e20 e40 e60 you get different titles like business, enterprise, megacorp or smth, something to work towards to. because like I said currently the most efficient strat is just to stay at scrap and minerals and keep prestiging until you know u have enough connections and knowledge. all the other content is only needed when you need to finally reach a certain gold count.
all in all, fun game in its early stages, but great music and lots of potential :D