Crusher spike blocks appear as blueish-grey squares with small spikes surrounding each of their four sides. There are ten spikes on each side of the block. They have black eyes that are shaped like thick lines, and they have small rectangular eyebrows, with ridges on the bottom. They have navy blue mustaches that are not connected together, and curl at the tips. Next to each mustache is a pink dot to mark their cheeks. On the top of the block is a large square of white from the reflected light.
When they fall down, the blocks' eyebrows will move down halfway over their eyes, giving them a more determined, serious look. Their eyebrows also lose their ridges. When they hit the ground, they shut their eyes for about a second, and then open them into their normal position as they float back up. When their eyes are closed, their eyes turn into smaller, horizontal lines, and their eyebrows slant downward.
Spike crusher blocks only appear in the attic of Hot Air's house, and are not present in any levels. Upon entering the attic, there is a spike crusher block, then the level thirteen door, then another block, then the level fourteen door, then a third block, and the level fifteen door. The blocks start at the ceiling, and then fall to the floor.
When they hit the floor a crashing sound is heard. After hitting the floor, they hold the position for about a second, and then begin floating upward to the ceiling again. It takes the blocks about six seconds to float from the floor ceiling and then fall again, so the player has to use that time to blow the balloon to the other side without touching the block in the process.
Hot Air Jr. can go over the blocks too, although they have less time to make it over - about four and a half seconds. If the balloon or its basket touch any part of a spike crusher block, they will die and have to start over at the last door pad they landed on.
- The same colours are used on the balls seen in a certain bonus levels of Hot Air Jr.
- Spike crusher blocks are similar to the crusher blocks in the game's prequel, Hot Air.
- Spike crusher blocks are the only enemy besides the purple bat and spike balls to not appear in a level. All three of these enemies are from Hot Air Jr.