After extensive troubleshooting, I've identified that this issue was not a bug in Captain of Industry, but rather a system-level global shortcut in KDE Plasma that was intercepting the Escape key.
Root Cause:
A custom shortcut in Plasma Workspace → "Activate Panel Widget" was bound to Esc alone. This caused the window manager to capture the Escape key before it could reach any application, resulting in:
Escape minimizing the game in fullscreen mode
Escape doing nothing in borderless/windowed mode
Applications losing focus when Escape was pressed
Solution:
Open System Settings → Shortcuts
Navigate to Plasma Workspace section
Find "Activate Panel Widget"
Either:
Delete the custom Esc binding (click the red X), or
Change it to a different shortcut like Shift+Esc
Log out and log back in
After making this change, Escape works correctly in:
Captain of Industry (opens game menu)
Firefox keyboard testers
Native Wayland applications like Kate
Confirmation:
✅ Two different keyboards tested
✅ evtest confirmed hardware was sending Esc events
✅ Issue persisted across game updates and system rollbacks
✅ Fix confirmed by multiple application tests
Closing:
Since this is a system configuration issue and not a game bug, I'm closing this report. Thank you for the excellent game, and I hope this helps any other Linux users who might encounter similar behavior!