Patch v1.3.1-alpha - minor changes and bug fixes

List of changes:

• Translate the text in "how-to-play" submenu to English
• Enlarge collision box at the end of the 1st level
• Add "options" button to the pause menu
• Add jellys to some places that had a dead end

List of bug-fixes:

•  Preserve volume settings in "options" submenu
• "Esc" button work not only to pause, but also to unpause the game
• Prevent music restart after death - now should continue playing the music
• Enemy projectiles don't recoil on checkpoint collision box
• Mouse Y-axis (pitch) movement affect camera rotation and not the whole capsule - control of character improved