Building upgrades at shop

Hi,

What are the building upgrades at the shop for. I just started with this game but even if I upgrade the powder machine to say lvl 3 it's only lvl1 when I buy it at the next game.

After you purchase the upgrades in the shop, they'll become available for you to buy during game play. When you've earned enough money to afford the upgrade during the level, you'll see the sign light up, then you can purchase the upgrade.

HTH!

Webwench is correct again. Buying an upgrade gives you the opportunity to BUY upgrades in the game.
Clicking the bubbeling items makes them work faster too.
Good luck.!