Geometry Dash Down Bass is a 1.9/2.0 solo Extreme Demon that was made by Spectra and initially hacked-verified.
As shown at the beginning of the level, where the lettering reads "Lime Circles" (changed to Down Bass in the most recent version), Down Bass is a Nine Circles level of high difficulty and has a lime color scheme. With buildings and cranes, the beginning and the conclusion are sunset-inspired. The level previously included 2.0 effects to sort of troll the player, but most of these effects have been eliminated. The user coins are still present on the level, and the decoration still has a strong 2.0 vibe.
User coins in Down Bass
When you get to 51% in the double-speed wave part, the first coin is pretty easy to get. The player just needs to take a short cut through some fake blocks to get there.
At 85%, the second coin is inside one of the dark rectangular shapes. You have to skip the blue ball at 84% on the first rectangle building so that you can land on the coin in the second rectangle building. After that, the player leaves the structure and goes back to the original road. This coin used to be at 32%, which is where the third key is now.
The third and final coin is well hidden so that it is hard to find by chance. To open the lock at the end of the level (in the last UFO part), the player has to find and collect all the hidden keys that are hidden in different parts of the level.