No multiplayer option for G-Force on PS2?

The specs for the game G-Force on Playstation 2 say "1 or 2 players."
However, when playing the game, we cannot figure out how to enable two-player mode. There does not seem to be a multiplayer option in any of the menus...
Both controllers are plugged in, but we only have one memory card. Could that have anything to do with it?
Both controllers work, and multiplayer does work in other games. The console is a PS2 slim.
Thanks for your help.
EDIT:
After taking another look at, it's only the dutch version that says 1 or 2 players... In French it says 1 player.
Pictures about "No multiplayer option for G-Force on PS2?"



Does G Force have multiplayer?
It was released for Microsoft Windows, Nintendo DS, PlayStation 2, PlayStation 3, PlayStation Portable, Wii, Xbox 360 and iOS....G-Force (video game)G-ForceMode(s)Single-player, multiplayer6 more rowsIs there multiplayer on PS2?
While the PlayStation 2 is known best for its JRPGs and franchise-establishing hits like the Metal Gear Solid games, that's not all it was. The console also had some great multiplayer games.How do you use multitap on PlayStation 2?
4 AnswersCan you play more than 2 players on PS2?
The PlayStation 2 is largely a two-player console, but the advent of Sony's multitap allowed more people to jump in on the multiplayer action. However, the average gamer remained unaware of many of the games that support this feature.G-Force PS2 Gameplay HD (PCSX2)
Sources: Stack Exchange - This article follows the attribution requirements of Stack Exchange and is licensed under CC BY-SA 3.0.
Images: RF._.studio, Suzy Hazelwood, Pixabay, Pixabay