It really doesn't. There's not even room for speeding and the point of the game is for it to be a relaxing and cozy game, what need do you have to rush it? Also, there are powerups for it to become faster.

Agreed, you're going to be making a lot of coins, and spending it on upgrades, including a faster boat. I like the chill paced aspect. This makes a great Steam Deck game.

At least in the Demo, there are 3 purchase options:

1. Upgrade the size of the Oil/Garbage Scoop
   
2. Upgrade the capacity of the Oil Holding Tank
   
3. Upgrade the power capacity

Option 3 provides increased speed and, to a limited degree, increased maneuverability. Mostly all that is self-explanitory.