This is a collection of glitches possible in Hey! Pikmin.
Please read the glitch notes before attempting any of these glitches or before adding your own.
Minor
Falling whistle glitch
On 3-A, go to the section where the Grown-Up Cell is, but do not whistle the Rock Pikmin hiding behind the bush. Go up to the treasure, collect it, and go near the edge to the left of it. then, walk and whistle at the same time. This will cause Olimar to fall down whilst the small cutscene is triggered. When the cutscene is over and the camera zooms out, Olimar will be stuck in the air for a short while, before eventually dropping to the ground, losing one bar of health, and respawning back at the edge. This glitch also works in the demo.
Sliding Pikmin stuck
On 3-A, go down the starting shaft, and head left, just before the shaft with slope crystals. Stand on the straight floor right before the drop, and look at the blue gems in the ground. Stand on top of the largest one, such that there's around one Olimar-width between you and the edge to the left. Notice the first slope crystal in the fall, wedged on the right side of the wall – it's consisted of one large crystal and a very small overhang crystal on top of the big one. Now, hold a Pikmin, aim the crosshair at the tip of the small overhang crystal, and release. The Pikmin should bounce on some crystals on the way, and eventually get stuck on the vertical wall of the same big crystal. The Pikmin will eventually get out, but slightly different positioning and throws can make the Pikmin hang on for more or less time. This glitch also works in the demo.