Nock Em is the second level of Geometry Dash SubZero and the first level with a Hard difficulty.
Nock Em introduces the wave and spider game modes, the green jump ring, and the size portals. It introduces the random trigger in the form of randomized 'Rub' text decorations as well, as seen in the image to the right. This level continues to showcase the new camera features, this time showcasing more of the static camera feature and introducing the Y-Axis locked option. This level also introduces for the first time the ability to disable the particle effects of the manipulation portals and the "End trigger".
- A cube sequence takes place from 0% to 31%;
- A wave sequence from 31% to 35%, while under the effects of the very fast speed portal from 31%;
- A ship sequence from 35% to 40%, with the very fast speed portal's effects sustained;
- A wave sequence from 40% to 45%, with the very fast speed portal's effects sustained;
- A ball sequence from 45% to 51%, with the very fast speed portal's effects ceasing at 51%;
- A cube sequence from 51% to 63%, while under the effects of the mirror portal from 53%, ceasing at 54%, continuing at 56% and ceasing at 57%, and while under the effects of the size portal from 62% to 63%, and while under the effects of the fast speed portal from 62% to 63%;
- A spider sequence from 63% to 68%, while under the effects of the very fast speed portal from 63%;
- A wave sequence from 68% to 73%, with the very fast speed portal's effects sustained;
- A ship sequence from 73% to 78%, with the very fast speed portal's effects sustained;
- A ball sequence from 78% to 83%, with the very fast speed portal's effects ceasing at 83%;
- A spider sequence from 83% to 82% (backtracking from 86%);
- And a cube sequence from 82% to 100% (backtracking from 82% to 78% and skipping from 81% to 97%), while under the effects of the fast speed portal from 82%.
- The first coin is located at 4% and collected as the cube. The player must go through fake blocks by jumping into the side of a floating platform. It will open up and make way, revealing the coin which the player can then collect.
- The second coin is located at 48% and collected as the ball. It requires a key to be collected, which can be found at 36% in the first ship part. Once the key is collected, a platform of invisible blocks will appear, forming a passage for the player to safely collect the coin. The coin is unobtainable without the key.
- The third coin is located at 84% and collected as the spider. After hitting the reverse jump ring and switching direction, the player must walk through a wall instead of avoiding it. The wall will disappear, revealing the coin. A well-timed click brings the player back to the original route.
- Collecting all three secret coins will reward an additional cube.
- There is a bug in the drop where if you jump right before the word "Out" appears on screen before the first wave sequence, you can skip the speed portal and play the following segments in the normal speed.
- It is possible to beat the level if this is done. The player needs to grab the key for the second coin, use the platform it creates to cross a gap, skip the second-last jump ring, then use the last ring late.
- Nock Em takes 102 seconds to complete and requires a minimum of 76 jumps.
- Nock Em is the only official level that visually indicates what gamemode the next section features in addition to portal indicators.