Some players wanted a better notification system, so I made a few quality-of-life improvements:

• Added a sound that plays when you run out of energy.
• Added a sound that plays when you run out of money.
• Added a sound that plays when you try to build in a non-buildable area.
• Added a sound that plays wehen you try to use an ability that is on cooldown.
• Improved the pop-up message for better readability.