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 37%;
- A wave sequence from 38% to 41%, while under the effects of the very fast speed portal from 38%;
- A ship sequence from 42% to 45%, with the very fast speed portal's effects sustained;
- A wave sequence from 45% to 49%, with the very fast speed portal's effects sustained;
- A ball sequence from 50% to 53%, with the very fast speed portal's effects ceasing at 51%;
- A cube sequence from 54% to 63%, while under the effects of the mirror portal from 56%, ceasing at 58%, continuing at 60% and ceasing at 62%, and while under the effects of the size portal from 67% to 68%, and while under the effects of the fast speed portal from 67% to 68%;
- A spider sequence from 69% to 72%, while under the effects of the very fast speed portal from 63%;
- A wave sequence from 73% to 76%, with the very fast speed portal's effects sustained;
- A ship sequence from 76% to 80%, with the very fast speed portal's effects sustained;
- A ball sequence from 81% to 84%, with the very fast speed portal's effects ceasing at 83%;
- A spider sequence from 85% to 91%;
- And a cube sequence from 92% to 100%, while under the effects of the fast speed portal from 84%.
- The first coin is located at 5% and collected as the cube. The player must go through fake blocks (with a red circle as indication) 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.
- Before Update 2.21.3, the blocks the player is required to jump through did not have any indication that they were fake.
- The second coin is located at 51% and collected as the ball. It requires a key to be collected, which can be found at 42% 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.
- Before Update 2.21.3, the key was much harder to collect, being located much closer to the spikes & being the same color as the background.
- The third coin is located at 90% and collected as the spider. After hitting the reverse jump ring and switching direction, the player must walk through a wall (indicated with dotted lines) instead of avoiding it. The wall will disappear, revealing the coin. After making two inputs to avoid two saw-blades, a well-timed click brings the player back to the original route.
- Before Update 2.21.3, there was no indication that the wall could be walked through. There were also no additional obstacles inside the wall.
- 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.
- However, this bug was fixed later on.
- 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.
- Before Update 2.21.3, when the player traveled backwards, the percentage decreased. This changed all the percentages in the level.