I got this bugged and fixed it, here is how I did it. However be careful and never trust random people telling you to edit files in regedit. Only do this if you know what you are doing.
Open regedit and edit the binary value "Resolution_XXXXXXXXXXX" at "Computer\HKEY_CURRENT_USER\SOFTWARE\Free Lives\Anger Foot". Change it back to the default which is "640 x 480 (59Hz).". This will allow you to relaunch the game and adjust the resolution safely.