Spikes (also referred to as blades in level 40) are hazards introduced in level 3 of Howmonica.
A spike has a grey circle with a pale centre. Surrounding the circle is a set of spokes that are a darker shade of grey. These spokes rotate around the circle.
Spikes appear in numerous groups in every level after being introduced in the third level. If Minni makes contact with one, she turns red, briefly disappears off the screen and the player is automatically forced to restart the level. They often line the outside of areas, creating barriers for the levels.
On level 40, moving spikes are introduced. These spikes look identical to the ones in the previous levels, except they have move in a continuous formation. When moving blades hit other spikes or blocks in their paths, they will start to move in the opposite direction.