People have been having trouble with this achievement for years, and a lot of people couldn't agree on how to unlock it. In this guide, I will share a consistent method of unlocking it. So far, it has been tested by myself and FunkeymonkeyTTR. It unlocked first try for both of us after trying this method. If you have any issues with this, feel free to comment and add me and I will do my best to help you.

Find the game in your Steam library, and click "Properties". Next, select "Betas" on the window that opens. Then, click the drop down that says "Select the beta you would like to opt into:". From this list, scroll down and select "1.3.3-1157350-vrworks-mrs - 1.3.3-1157350-vrworks-mrs." Picture is included below for reference. The beta you need to select is circled.

Note: You may be able to obtain this on the beta with VR enabled, however, it's only been tested with VR disabled.

To launch the game without VR, simply unplug your headset and close SteamVR and launch the game. This will start the game in a non-VR mode where you use your WASD keys to move and press the space bar to move to different games. Once you are at balloon knight, play the game by clicking the clowns to punch them. You will rack up points extremely quickly when playing in non-VR mode. Upon reaching the score required for the large prize, you will earn the achievement.