app resolution tick box

hope this is the right place to post,
I know nothing about mac,
I just downloaded an app "splode"
after it installed I launched it and it came up with a box asking what resolution I would like, I left it at the default setting and the game launched at full screen,
the next time I launched the game, the same box came up asking about which res to use, this time I kept it at the default setting, but this time I ticked the box that said "do not show this box again" then when the game launched it wasnt full screen,
there is an option at the top to go full screen, but as it launched full screen before I ticked the box I would like to know..
1, how do I get the option box back to show each time, as I cant find an option anyplace to see that box again to untick it.
2, can I get th app to launch full screen like it did first off.
many thanks for any help.
steve.

1. Most apps with this option let you hold down the Option key at startup to get the box back.
2. Depends on the app.

thanks very much for the help, it worked...once I found out what the option key was
thanks again.