Hi pigtrooper, thanks for reaching out!
Normally you have two options for charming:
1. If you are using a 3 button mouse, you can charm with the middle mouse button (usually the scroll wheel)
2. If you are using a gamepad (like a xbox360 or ps4 controller) you can charm using the L1 or R1 shoulder buttons.
You know when you are charming if it looks like in the image below
Charming enemies fills up a gold colored charming bar over their heads, below their health bar. Successfully charmed enemies start to glitter like Susi and stop shooting at you.
We really hope that this works for you with your current hardware setup. Unfortunately as this was made as a GameJam project in 2017 and we don't support it anymore. So changing controls or anything about the game is very unlikely to happen. We also don't have a Mac anymore for testing purposes.
We hope that you still have fun with the game, even if the charming mechanic does not work for you!