The Callisto Protocol (referred to simply as Callisto from here on out) is a survival horror game developed by Striking Distance Studios. Released in December of last year, you play as intergalactic cargo pilot Jacob Lee whose spaceship crash lands on Jupiter’s moon, Callisto.

Callisto’s 5th level, Lost, is one of the most hated levels among the Callisto community. Before the developers added cutscene skips in an update earlier this year, this level would clock in around 30 minutes glitchless. Lost features several lengthy cutscenes, frustrating combat sections, autoscrollers, and lots of downtime.

Lost I, II, & III

In Callisto, checkpoints are only loaded once the corresponding map file is loaded in memory, meaning it is not possible to skip from one map to another, even if the coordinates in the game world overlap. Skipping from a checkpoint earlier in a map to one later on is fair game.

Lost is broken up into three map files.

• Snowcat_Persistent (Lost I)
• Hanger_Persistent (Lost II)
• Europa_Tunnels_Persistent (Lost III)

Snowcat is the first and longest section, Hanger is the second section and is mostly unskippable cutscenes and story stuff, Tunnels is only a single cutscene. For this piece, I will only be talking about the first section of Lost, Snowcat, as it is the only notable section of this level.

Early Days of Lost Skip

On December 7th 2022, less than a week after Callisto was released, community member @Symystery would unknowingly post the first step to Lost Skip. Symystery had found a way to walk out of bounds before the first frustrating fight scene. He said that he thought it wasn’t useful. He would be correct, this discovery wasn’t useful yet. Little did the community know that this would open the door for one of the biggest skips in the run.

New Tech

A month later, on January 4th, @Looney would find a new tech called Inventory Hovering.

Jacob has an inventory that he can open by pressing TAB where he can view his arsenal and gear up for combat. Once you press TAB, Jacob’s momentum starts to slow down and then comes to a halt a second later. Once stopped, his coordinates in the game world become frozen until he is either attacked by an enemy or closes the inventory. By opening the inventory as soon as you hit certain collision while dropping from an elevated surface, Jacob is able to maintain the frozen Z coordinate (The player's height) but his X and Y will continue to move in the direction of the collision. This allows the player to fly through the air in the direction the collision sends them.

You may think that this sounds really broken, and it is, but it has its problems. For one it doesn’t work on every piece of collision, you usually have to hit some kind of sloped or angled surface. Hovering through the air is also much slower than running speed so you have to make sure whatever you are skipping by doing the hover is faster than just running through the level.

The First Breakthrough

A few days later, Looney would find a way to use the new Inventory Hover tech combined with the out of bounds Symystery had posted a month earlier to fly into the out of bounds space to hover over a large death barrier which would instantly kill anything that touched it.

Once out of bounds, he found a way to scale the large mountain in front of the player.

Navigating the out of bounds space is very difficult because everything is extremely low detail to save on resources. Most of the textures do not match the actual collision that is present in the game world, meaning in some instances you are able to walk on what seems like thin air. If you stray too far from the path up the mountain the level will also unload. Additionally, there is invisible collision all over the out of bounds space, and you need to do some certain camera movements to unload them. All of this combined made finding a good path to take to the top of the mountain difficult, but not impossible.

From the top of this mountain you can do a precise setup to get stuck inside of a rock and do another piece of tech called a Stomp Launch to fly thousands of coordinates towards Jacob’s ship which has the final cutscene required to complete the first part of Lost.

Stomp Launches

If the player stomps into certain collision, Jacob will go flying through the air backwards. We can use this to cross decently sized gaps or holes. We do this in a few other parts of the game, like the start of Outbreak to skip the entire level.

If Jacob is stuck inside of collision, the collision unloads, and then the player stomps at the same time - Jacob will fly thousands and thousands of coordinates backwards. You can aim where he will launch if you aim Jacob’s back in the direction you wish to fly towards. Once in the air Jacob will only stop if he hits a wall, a floor, or if the player reloads the last checkpoint.

There are many factors that determine how far of a Stomp Launch you will get. Some of these things include:

• The player’s angle towards the object
• The timing on when the player stomps (how early/late)
• How deep the player is in the collision
• The current framerate/FPS (higher = farther launches)

Due to stomps being determined by the framerate, the Callisto community decided to put a cap of no higher than 120 FPS to try and mitigate hardware discrepancies between runners.

Patch 1.8

In April, Striking Distance Studios released patch 1.8 that allowed the player to skip almost all cutscenes in the game. This saved almost 1 hour in glitchless. You might think that this would have a big impact on the run, but you would be wrong

In the same update Striking Distance Studios fixed the very first out of bounds that made Lost Skip possible in the first place. They raised the invisible wall, meaning it was no longer possible to get out of bounds the same way we used too.

A few months prior, Striking Distance also patched Aftermath Skip, which saved around 15 minutes with cutscene skips. This was no problem for the community, as we would simply play on the fastest version by downpatching - but this was different.

Since Lost Skip saved around 12 minutes with the cutscene skips combined with the fact that they had patched Aftermath Skip in a previous update (which saved nearly 20 minutes) this made the patch with cutscene skips slower than the one where you had to sit through all of the unskippable cinematics.

The community was pretty upset. They had released an update to skip almost all of the down time and optimally it wasn’t even faster to play on this version. Some community members returned, and we saw @sharkhat lower the world record by a few minutes with cutscene skips, but the community knew it could go much lower on the old patch

Early Leads

The community wasn’t ready to give up. We knew that if we found any way to get out of bounds again it was possible. Looney, Sharkhat, and Symystery would go looking for Lost skip again on the cutscene skip patch. Symystery had posted a theory only a day after 1.8 was released, where you could get a stomp launch earlier a little earlier in the level.

Unfortunately - nothing ever came from this particular discovery.

Where We Are Today

Thankfully, a few days later Symystery would find a way to do Lost Skip on cutscene skip patch, which officially made the version with cutscene skips faster than without.

Currently Lost I sits around a comfortable 8 minutes, significantly better than the 30 minute grind it used to be before Lost Skip and the addition of skippable cutscenes.

I want to give a big shoutout to @Looney and the rest of the Callisto speedrunning community, because without everyone working together we never would have been able to find as much as we did in Callisto.

Is the game solved? Definitely not, there are certainly discoveries yet to be made and sub 1 hour seems like it is within reach - but only time will tell.