In the Flash game I can't double click to zoom, and the p/m keyboard shortcut suggested on the wiki doesn't work either. I also can't scroll with the mouse to zoom, that doesn't do anything either. Is there a shortcut on the keyboard to zoom in or out, or a way to do it with the mouse other than clicking the buttons directly? Thank you.

Try the + and - keys. If that doesn't do anything, use your browser's zooming shortcuts (e.g. Ctrl + zooms in for FF).
If I find a way that works on my end, I'll post it here.

Edit:
On Flash, + and - keys as well as browser default zoom doesn't zoom in or out.
On Unity, the + and - as well as p and m and browser default zoom zooms in and out.
Tested in FF60.0.2.
Sent bug report.

Edited 6/24/2018 08:55:13