CelSector A1 Walkthrough: Prison Sector Route and Chests
A full CelSector A1 route: the larvae pit keycard, the egg arena, the SMG room and the three clothing chests most players walk past.
Quick answer: A1 is the prison sector and the game's tutorial. The critical path is the larvae hall, the egg arena and the exit door, but the sector hides the first keycard in a pit, the SMG in a side room and three clothing chests around that room. Clear the side content before the final door.
A1 is short enough to finish in one push and small enough that missing a chest feels like a waste. This route covers the critical path first, then the sweep.
The first keycard sits at the bottom of the larvae pit. If the exit is locked, you skipped it.
Route overview
| Step | Room | What happens |
|---|---|---|
| 1 | Starting corridor | Learn movement, pistol and the grab escape |
| 2 | First larvae hall | Drop into the pit for the first keycard |
| 3 | Larva egg arena | Clear the arena for the final keycard |
| 4 | SMG room | Take the SMG and the clothing chests |
| 5 | Maggot pit | Bottom-right chest |
| 6 | Exit door | Use the keycard |
Step 1: the opening corridor
The first room teaches the two systems that matter: the pistol has infinite ammo, and enemies can grab you. Shoot the first mutants at range, let them come to you, and practice the struggle input if one closes.
Do not waste shotgun or SMG ammo here; you do not have them yet. The starter pistol is enough.
Step 2: the larvae hall pit
The first larvae hall has a pit that looks like a hazard. It is the route to the first keycard.
- Clear the larvae around the pit first.
- Drop in deliberately.
- Follow the lower path to the keycard.
- Climb back out.
If you walk past the pit, you will reach the locked door without the card and have to come back. The secrets page→ lists this as the sector's most-missed pickup.
Step 3: the larva egg arena
The egg arena is a closed fight. The arena spawns larvae in waves, and the final keycard drops when it is cleared.
Practical notes:
- Keep moving; the eggs limit your dodge space.
- Use the pistol on singles and save any pickups for the last wave.
- Check the far side of the arena after the fight; the card is not always in the centre.
Step 4: the SMG room
The SMG room is the sector's treasure room and the easiest place to under-clear.
| Pickup | Location |
|---|---|
| SMG | Left side of the room |
| Clothing chest (top) | Left wall, above the SMG |
| Shorts, hair and bra chests | Outer left of the room, three separate pickups |
| Ammo | Scattered around the room |
Take the SMG last. If you grab it and leave, you will miss the chests on the same wall.
The SMG is the first automatic weapon and the answer to the sector's larvae crowds. It burns ammo, so switch back to the pistol for singles.
Step 5: the maggot pit
The maggot pit is a lower area with a chest at the bottom right. Drop in, clear the maggots, take the chest, and climb out. The pit is optional, but the chest counts toward the clothing collection.
Step 6: the exit
The exit door needs the arena keycard. Before you open it, confirm:
- First keycard from the larvae pit
- Arena keycard
- SMG
- Three clothing chests around the SMG room
- Maggot pit chest
If any box is empty, the sector is replayable with stage select, but doing it now is faster.
A1 enemies
| Enemy | Threat | Answer |
|---|---|---|
| Mutants | Melee, can grab | Pistol at range, struggle if grabbed |
| Larvae | Small, swarm | SMG or pistol, keep moving |
| Maggots | Pit ambush | Clear before dropping |
The combat tips page→ covers target priority; the grab guide→ covers the escape.
A1 and the demo
The demo covers this sector with a content cap. If you played the demo, the route will feel familiar; the retail build adds the full clothing set and the later weapons. See the demo save page→.
FAQ
Did I miss the first keycard? If the exit door is locked and you have not dropped into the larvae pit, yes.
Is the SMG worth taking? Yes. It is the first crowd-control weapon and it carries A1 and A2.
Can I replay A1? Yes, with stage select after the sector is cleared.
Sources
Official source: CelSector on Steam ↗ · CelSector demo on itch.io ↗ · Steam news and patch notes ↗