The player character is Nutty, who has to throw a ping pong ball into a cup of milk on the opposite side of a table. Every round of the game is the same. The round begins with Nutty hovering his hand around the screen while holding a ping pong ball. When Nutty's hand hovers over the cup, the cup will be highlighted by an orange glow. When the cup is highlighted, that is the right moment to click.
If the player manages to make the ball land in the cup, Lumpy is forced to drink a cup of milk, and the player proceeds to the next round. If the player misses, Lumpy will either give a sigh of relief or say "Mm-hm." etc., which results in the player having to replay the round. There are a total of five rounds.
Lumpy and Nutty are playing "milk pong", exactly like beer pong, only using milk instead of beer (probably to make it fit the show's "kid-friendly" style).
Nutty bounces a ping pong ball and it teeters on the rim of the cup. Lumpy tries to prevent the ball from falling in by slamming his fist on the table.
Hit: If the ball lands in the cup, a dismayed Lumpy is forced to drink the cup of milk, but accidentally swallows the ball along with it. He eventually coughs it up and the two continue playing.
Miss: If the ball falls off the rim of the cup, Lumpy gives a sigh of relief.
Nutty throws the ball, but overshoots the cup. First, the ball bounces into a scene resembling Eyes Cold Lemonade, where it ricochets off Petunia and Giggles' lemonade stand. Second, it bounces into an exact replica of Water Way to Go, where it hits Pop, causing him to drop the bowls of ice cream he was getting for Cub from the ice cream truck. Frustrated, he asks Cro-Marmot, the ice cream man, for two more bowls. Lastly, the ball bounces into a replica of Get Whale Soon, where it puts out Russell and Lumpy's bonfire inside the whale. The ball then bounces back into the game.
Hit: If the ball bounces into the cup, Lumpy, again dismayed, reaches for some milk. However, he unknowingly grabs and drinks some clothing bleach instead, resulting in his tongue becoming discolored and pale upon drinking the cleaning substitute.
Miss: If the ball fails to land in the cup, Lumpy will shout "A-ha!"
Nutty shoots his ball again and, as usual, it teeters on the rim. This time, Lumpy proceeds to blow the ball off the rim with a hair dryer.
Hit: If the ball lands in the cup, Lumpy proceeds to drink some milk. After taking a sip, Lumpy notices a rat inside the cup, prompting Lumpy to spit the milk in his mouth out and give a shocked look.
Miss: If the ball fails to fall into the cup, Lumpy will do a fist pump and say "Yeah!"
Hit: Nutty tosses the ball, and it lands on the rim of the cup. Lumpy once again uses the hair dryer to blow the ball off the rim, but instead the ball lands in the cup. Lumpy proceeds to drink some milk, and after a few seconds, his stomach gurgles. Lumpy quickly realizes this, and he dashes into a nearby outhouse. He then comes back (off-screen) to continue the game.
Miss: Nutty tosses the ball, but the ball bounces over the cup, and it ricochets off a tree. Lumpy then uses a ping pong paddle to knock the ball away. The ball then bounces off the rim and falls off. This makes Lumpy raise his arms and shout "Yay!"
Ball 5 - Ending #1
Nutty shoots his ball and once more it is on the rim of the cup. Not learning from his past mistakes, Lumpy again uses a hair dryer to knock the cup down, but again knocks the ball into the cup. He drinks the milk, but to his horror he finds another rat, which reveals a set of sharp teeth and devours Lumpy's face.
Ball 5 - Ending #2
Nutty overshoots his ball and it bounces off a tree to Lumpy. He knocks the ball away with a ping pong paddle, but it bounces into the cup. He reaches for the cup but accidentally knocks it over, causing the ping pong ball to bounce into a nearby wood chipper, which jams the blades. Lumpy reaches in with his hand and, surprisingly, retrieves the ball without harm. He happily turns around to resume playing, but is crushed by a tree that Handy and The Mole were chopping down. Handy then looks at the player in surprise.
Miss: Nutty tosses the ball, and it lands on the rim of the cup. Lumpy then takes a big breath, blows, and successfully makes the cup fall over. Lumpy then crosses his arms and says "Mm-hm."
Note: Both Ball #5's will have the same miss.
- A rat gnaws off Lumpy's face. (Ending #1)
- Lumpy is crushed when a tree falls on him. (Ending #2)
- Lumpy nearly chokes on the ping-pong ball trying to drink the milk from the cup. (Ball 1)
- Lumpy accidentally drinks bleach instead of milk, bleaching his tongue. (Ball 2)
- Lumpy's stomach rumbles after drinking some milk, making him run into an outhouse. It can be assumed that he got diarrhea. (Ball 4)
- It would be almost impossible for Lumpy to get from the game to the whale and back before the ball did (however, this was used for comedic effect, so this is most likely done on purpose).
- In the first ending, after Lumpy's face is bitten off by the rat, a tooth can be seen above his nostrils.
- In the second ending, Lumpy's antlers are inverted while he is looking into the wood chipper.
- Since the game is played outside, it is unknown where the hair dryer in Ball 3 is plugged into.
- There is a glitch in the game where on the Mondo official site. When the game is completed, the "Play Again" button does not work. Instead, the page has to be refreshed to start again.
- This is the only game that crosses over between episodes (i.e. Lumpy and Russell inside a whale's stomach from Get Whale Soon, Pop buying an ice cream from Water Way to Go, and Giggles and Petunia setting up a lemonade stand from Eyes Cold Lemonade).
- This is the first Happy Tree Friends interactive YouTube game. The second interactive YouTube game is Double Vision.
- This is the second time Pop appears without Cub, the others being his BBQ Smoochie, Something Fishy, and Tunnel Vision.
- The scene where the ping pong ball crosses over between episodes may have triggered an episode's outcome or setting (a notable example is Eyes Cold Lemonade, where the ball hitting the stand could have caused the sign to fall down and slash Giggles' face).
- Ending #1 can only be seen on the YouTube version of the game, and Ending #2 can only be seen on the HTF website.
- This is one of the few episodes where Pop is missing his pipe for the entirety of the episode.
- Lumpy's death in Ending #2 is similar to Giggles death in Snow Place to Go.
- In every round of the game, Nutty's movements are exactly the same.
- All of the episode look-alikes that the ball bounces through in Round 2 are Season 2 episodes.
- As this game was made after the TV series, however, the characters have their post-TV series designs rather than their Season 2 designs.
- Lumpy having to run into an outhouse is reminiscent of him doing the same thing in A Hole Lotta Love.