Nock Em is the second level of Geometry Dash SubZero and the first level with a Hard difficulty.
Nock Em introduces the Spider and Wave gamemodes, the green gravity orb and the size portals. 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".
- The first coin can be located at 4%. All you have to do is jump early to a floating platform. The platform will open up and make way to a descending coin.
- The second coin can be acquired at 47%. In order to be able to collect it, you must attain a key in the first ship, at 36%, which is located near the ceiling. The coin itself is located at a ball part, where a platform of invisible blocks will appear when the key is collected.
- The third coin is located at 84%. After hitting the orb and switching direction in the spider part, let the spider walk directly into a wall. The wall will then reveal a coin. Afterwards, make a well-timed click to go back to the original route.
- There is a bug at the drop where if you jump right before the word "Out" appears on screen, you can skip a speed portal and play the following segments in the Slow 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 orb, then use the last orb late.
- Nock Em marks the return of the mirror portal, found in the black static camera section, and was last used in Geometry Dash World in the level Striker.
- This is the fourth level to include a secret coin which requires a key to unlock it, the first being Deadlocked, the second being Viking Arena, and the third being Airborne Robots.
- This level skips from 87% to 98% near the very end of the level, making use of the new "End Trigger".
- It is the first official level to use both the Ball and spider Portals in the same level.
- This is the first official level in Geometry Dash with a song made by Bossfight.