Thank you for playing,
For the first point we already knew that going in to the jam but we thought that multiplayer was the way to go for this game. We did not want to implement online multiplayer as it would have brought many more problems. The way we tested and played the game was via Parsec which worked surprisingly well.
I totally agree with the second point the aiming for the mouse and keyboard player is far easier than for the rest of them. However as you said it would be very difficult to circumvent that issue, we could have not supported M&K but I am sure that most of the players will appreciate the M&K support.
For the last point we could not test it with DualShock4 controller and we simply hoped that the Unity Input System supported PlayStation Controllers.
Thank you again for your feedback.