​Minor tweaks and bug fixes​

Minor tweaks and bug fixes

• Pressing Enter starts the game and try again.
• Pressing Backspace returns you to the title screen.
• Decreases the time between Rounds so you don't have to wait so long.
• I removed the heart at the top, because it's just one life ;P
• Changed the name "Game Over" to "You lost".
• Removed an annoying "onclick" error.