Thank you so much for this very detailed feedback, we really appreciate it!!
We will have a look at the combat system and try to make it a bit diverse, not jsut right-cliking^^
Also we think that putting some particle effect on to the grappling sign could work very well, thank you for the idea!
And finally we are sorry the boss didn't spawn, other users reported the same bug and we will try to solve it as soon as possible, and the chest of gold will eventualy contain something valuable.
Thanks for your time and feedback again^^