The devs are listening and we are more than happy that you are not reporting too many bugs! :)
We fixed a few things in the game:

• Fixed timings on some levels
• Added support for binding more mouse buttons
• Fixed problems with control bindings resetting
• Fixed endless mode shooting bug
• Fixed restart bug in hardcore speedrun mode

SEUM Demo was still in beta version and today we updated it to the current state of the game. Check it out and try 11 levels for free!