Unfortunately there is a bug, which makes it unplayable on 21:9 monitors. 

The bug is -starting a new game and if you switch to the weapons menu, the HUD / UI is overlaping the "close" button for exiting the menu.

Is there a workaround? 

Pressing ESC does not work, neither switching to a non 21:9 resolution. 

I really like your game, and want to play it. Here is a screenshot for better understanding what I mean. https://ibb.co/P4000td

Thanks for reporting. No there's no easy workaround. I'll have to fix it in the editor. But good news is it's an easy fix and I'll include it in the next version which will be available soon!

EDIT: So I fixed the issue. If you try the next version, please get back to me with your results. Also if you could let me know what the Transceiver screen looks like that would be great! I changed it a bit in this next version, so now you have me worried some elements aren't going to fit together right. Thanks! Hope to hear back. Next version will be live in the coming week:)

Thank you for the quick response.

I'll check it out after your next release, and give you an update on this.

Best regards Tadashi