-Sirius- is a 2.0 demon created by FunnyGame. It is praised for its incredible effects and for being one of the first levels to introduce a boss fight. The level is rated as a medium demon and is FunnyGame's second most downloaded demon ever, (After Crazy Bolt).
The player starts with a cube segment with spikes double their normal size appearing one after another. The player will have to time their jumps to the beat in order to jump over all of them. The red and black background is custom made and featured several decorative spikes along with lots of depth to it. The text "-Sirius-" and "FunnyGame" can be seen beating to the song in the background, and "♪ MafiaPineapple - Genesis" on the upper black border showing off the song of the level, also beating to the song.
A teleportation portal takes the player to a green and blue ball maze, with a colorful background moving to the beat. The blocks used as the path also beat in the form of flashing white for a brief moment. Quite early into this part, the ball will turn mini and go on as before through the maze. Two moving green orbs then appear right before a wall of teleportation portals. Right after that, the player must time a press in order to hit a yellow jump pad sending the ball forward. More navigation follows along with a few gravity portals and an invisible size portal as another teleportation portal sends the player to the next part.
At this segment, the player transforms into a decently simple ship. The hazards at this part consists of parallax effect squares which need to be flown through as they follow the player as well as spikes all along the floor and cealing. The background here if filled with green circular motifs over a black background, all spinning and moving to the beat of the song. After this, the song will start building up, and the ship will become auto and appear to move much faster due to the objects moving towards the left of the screen, consisting of rapidly moving slopes against a white background with a bunch of squares in different shades of gray, all beating very rapidly. About halfway through, the song will build up even more as the screen shrinks in from both the top and bottom, which after a while stops and shows a red text saying "WARNING!!" along with the boss being shown right before the fight.
The song hits the drop and the player will transform into a wave with a flashy, red background and the boss consisting of two spike-like creatures on both the left and right side of the screen. The boss will shoot custom-made spikes from both sides that move very quickly over the screen. The first wave of spikes can be avoided by sliding across the ground for a while before moving up for a single spike. Wave #2 will require the player to straight wave in the middle to avoid the spikes coming in from both the top and bottom. The two creatures will then lunge towards the player in three beats before the 3rd wave of spikes. Here the player can begin by sliding across the ground once again but must then move up to avoid the spikes being shot from the right-side boss. The final spike barrage consists of diagonally moving spikes which can be avoided in several different ways right before the boss performs three more lunges towards the player.
After this, the left-side boss will disappear and the right-side boss will begin to shoot lasers and more spikes in four new waves of hazards. Firstly, the boss will shoot lasers from the top to the bottom of the screen and fire spikes at the top. In the second wave, lasers will be shot at the bottom and the boss will move towards the player, forcing them to move to the top of the screen for a moment. Wave number three will begin with the boss firing lasers at the top and spikes at the bottom right afterwards. Finally, lasers will be shot from the bottom towards the middle just before the player enters a teleportation portal signalling the final part of the level.
Here the player will transform into a normal size robot sequence and the background will turn dark purple. The gameplay consists of lots of memorization and timing the robot jumps in order to land on a ton of platforms over a blanket of clouds just underneath. The boss will here launch purple orbs of varying sizes at the player which need to be avoided by jumping onto the correct platforms. After each quarter of this part, the boss will, as before, lunge at the player from right to left. Halfway through, the boss' eye will turn purple and it will begin to shoot a mix of both lasers and orbs, although this time, the boss shoots double lasers. If the player manages to avoid the three final orbs launched, the boss will disappear and "Clear!!!" can be seen as the background turns white and the level is beaten.
- The first coin is located near the sixth giant spike on the ground at 8%, to the left of a hanging spike. After the player jumps over the sixth spike, he or she must jump again to obtain the coin. Jumping too late could cause the player to crash into the hanging spike.
- Coin #2 is located near the ceiling before the short auto part, around 34%. The player must fly up immediately while the background is transitioning to a white color.
- The final coin is located near the ceiling before the boss shoots the first wave of lasers, around 60%. When the boss begins to fire lasers, go up to the ceiling to collect the coin. Going up too early will cause you to crash into the line of monsters above.
- If you die at the first hanging spike, a lenny face appears.
- This can be triggered without killing the player. The player needs to jump right after getting past the hanging spike.
- AssadaWarrior's fans claimed he beat this level in 7 attempts, he says it took 28.
- Despite the huge amount of decorations, FunnyGame managed to build this in exactly 30K objects.
- The level has started a trend similar to that of the Nine Circles Levels after a level named "Nibiru" by RenzorGD with the same design of Sirius, although green in main colour, was uploaded. A yellow Sirius remake named R4zor has also been sighted.
- The only such remake with a star rating is SiriusX created by Manix648, which is also a featured demon.
- On Dec 20 2015, Funnygame jokingly uploaded a video onto his Youtube showing the bosses decorated as Christmas trees. However, this was never actually uploaded on Geometry Dash:
- Collecting the first user coin will change FunnyGame's name in the title to BunnyGame, a running gag in FunnyGame's 2.0 levels that references his nickname.
- Upon finishing the level, if the player were to wait 30 seconds after the menu appears, the white background will fade to black, revealing a low-resolution mispelling of the nickname as BunyGaem.
- On FunnyGame's profile, he states that he should rename "-Sirius-" to "Sirius".