Okay, so what you wanna do is click the green sign in the top-right corner of the screen which says 'More!' on it.



Then you should come to a sort of glorified options menu, and the first thing you should see is the brony mode selected. How convenient!



If it says that you have to pay for it, then you probably got the game before it became paid. In that case, you'll have to buy it as DLC. If you bought the game with money, then it should be free. Just unlock the mode and then click the switch to turn your generic stuffed toys into generic stuffed ponies! :D

If you look through the menu, you can see that Snuggle Truck comes with a lot of free DLC, including new level and a new powerup for the level editor! It also has a ton of different truck designs. If you don't like Brony Mode, why not play the game with pandas? Enjoy!