DUAL MONITOR ISSUES in games - if your game starts on the wrong monitor and the game has no settings to fix this issue try this (thanks to the Devs at WeirdBeard for this solution!):

Here are the steps to getting the game to run on the correct monitor:

[STEP 1]: Open Regedit. If you are on a Windows machine you can type in "regedit" into the windows search bar at the bottom left of your screen then press enter/return to run the command. If you have windows search disabled you can press both the 'WINDOWS' and 'R' key together to open the "Run" dialog box. Within the text field type in "regedit", then press okay.

(see below for more instructions)

[STEP 2]: Alright so you now have the registry editor open. Now you need to navigate to HKEY_CURRENT_USER\SOFTWARE\ game company \ game name

Example: HKEY_CURRENT_USER\SOFTWARE\WeirdBeard\Tricky Towers

[STEP 3]: Double click UnitySelectMonitor and change the "value data:" to whatever monitor you want to open the game as. If you are unsure, then start at 0 and open the game. If this doesn't work increment the number by one and relaunch the game. Repeat this until the game launches on your desired monitor.

Monitor "1" worked for me.