1. Opening the game- Tap the Despicable Me: Minion Rush icon on your mobile device to open the game.
2. The shop- Tap on the shop to open it up. Here you can buy costumes, Gru coins, bananas, and get your power-ups.
3. Power-ups- Once you are in the Shop, tap the star icon at the top right of the screen. Here you will find a list of the power-ups available.
4. Upgrading- Each power-up has upgrade potential. All power-up upgrades cost bananas with the exception of the PX41 Serum (upgrades cost Gru Tokens). All power-ups will have a button to the right showing the bananas it will cost you for that particular upgrade. Tap the green button next to the power-up you wish to upgrade. As you would expect, the cost of the upgrades gets higher with each upgrade to the power-up selected.