Thanks for asking this question :)
Sorry to hear, that there are problems with the controls. Pressing space should indeed trigger the jump! It's the first time we hear this feedback.
Please try using an external keyboard on the mac or use an XBOX/PS4 controller. If this doesn't work, maybe you have access to a PC with Windows, so you can use the Windows-version of Falling Awake.
Please consider, that during the start screen in the bedroom there is no jump possible. The jump will be activated after the game starts (when Maya goes to bed).
We hope this will fix it and you can enjoy playing Falling Awake. Otherwise, feel free to write back.