Video games and boobs are a perfect combination, but this is ridiculous. Sega’s Super Monkey Ball series is a popular franchise for gamers of all ages, letting you roll a transparent ball containing a cute little monkey over a variety of challenging courses, picking up bananas and trying to get the best time.

2012’s Super Monkey Ball: Banana Splitz was the tenth game in the series and first for the PlayStation Vita. Using the portable console’s tilt controls was a fun new wrinkle onto the gameplay, but after ten games it can be hard to find a good PR spin for a title like this.

Sega hired Japanese model Yukie Kawamura to pitch the product, and released a number of commercials starring the busty bikini-clad model. They were so popular internally that the developer decided to put Kawamura in the game itself, in typically weird fashion.

The “Adult Challenges,” which are only available in the first Japanese edition of Super Monkey Ball Banana Splitz, feature the same obstacle course action as the others, but with a few wrinkles. The sky around you is replaced by huge pictures of Kawamura, and instead of hills on the ground, you need to get up enough momentum to launch off of the model’s (admittedly very nice) boobs.

The video above shows off the Adult Challenges. For all this promotion, Super Monkey Ball Banana Splitz only got a 66 on Metacritic. The Vita never really caught on outside of Japan, which probably didn’t help. Congrats to Kawamura on her awesome boobs, though.