Frogger: Helmet Chaos is a top-down platform game with the eighties' arcade frog as the protagonist, but now in 3d. The basic gameplay is still the game, as the frog moves one (invisible) square per key press, which maintains the feel of the original arcade game instead of the modern, smoother movement mechanics.
When Frogger climbs a tree to get some moonfruit for Toady, his friend is gone when he returns. He follows his footprints and finds out Toady is under the control of Dr. Wani, who has ordered his mini-crocs to place mind-control helmets on all residents of the land. It is up to Frogger to undo this.
The game consists of different small levels with puzzle elements. Frogger can be moved around with one square per movement, or two for a regular jump. This mechanic is most often used to navigate maze-like platforms with water. Ironically, Frogger drowns when touching liquid. While moving around he can collect coins and there are checkpoints to save progress. He can use his tongue to push or pull objects, or swing from branches. There is also a vertical jump to reach objects mid-air and he can turn 90 degrees to face a different direction. The frog has a limited amount of lives, but one can be restored by picking up an apple.
The story is continued through drawn cut-scene sequences with static images and voice-overs (on the PSP, there is only written text for the DS version). The PSP version supports game sharing, while the DS top screen shows the game statistics while playing the story mode. There are also seven mini-games, including the original arcade Frogger but with polished graphics, and hats and costumes to unlock with the collected coins.