Minor Fixes — Logic Bombs Steam update #1318812

PC Version: The return (enter) key can now be used to navigate menus. Mouse and keyboard controls can now be viewed from the options screen. The initial intro sequence now mentions how to view mouse/keyboard controls. Pressing Escape on the level select screen will no longer quit the game immediately, it will take you to the options screen. You can quit the game from there. Modified the background for 4-2 to improve clarity. Puzzle is unchanged. Fixed a visual bug on the level select screen introduced in the last patch. Fixed a crash that could occur if rumble was enabled but a rumble incapable controller was connected.