How to Get the Alien Key in Sell Lemons (July 2026) — Full Guide

How to Get the Alien Key in Sell Lemons

The Alien Key is one of the most sought-after hidden items in Sell Lemons. Players searching for how to get the alien key in sell lemons are usually trying to unlock the secret alien room, which contains a powerful permanent upgrade: the Alien Investor bonus.

In this guide, we will walk you through everything you need to know about the Alien Key, how it relates to the UFO Key, and how to claim the Alien Investor for a permanent +2% cash bonus on every investor you own.

For related content, see our UFO Key guide, Sewer Key guide, and investors guide.

What Is the Alien Key?

The Alien Key is the second hidden key found within the underground sewer maze system in Sell Lemons. While the Sewer Key unlocks the Cosmic Cash Vine gate, the Alien Key (also referred to as the UFO Key by many players) opens a mysterious door leading to an alien visitor.

Here is how the keys differ:

Many players refer to the UFO Key and Alien Key as the same item because they unlock the same alien-related content. The key is found using a more complex lever sequence than the Sewer Key, requiring all four colored levers.

How to Get the Alien Key: Step-by-Step

Before attempting the Alien Key route, you should already have the Sewer Key completed, as the alien door is located deeper in the maze past the sewer key area.

Prerequisites

• Join a fresh server to ensure all levers are in their default positions
• Know the cardinal layout of the sewer maze (Blue=NE, Red=SW, Green=SE, Purple=NW)
• Have the Sewer Key already obtained

The 9-Step Alien Key Lever Sequence

Follow this exact order to reveal and claim the Alien Key:

After each lever interaction, use the respawn button to teleport back to the sewer entrance. This saves time compared to walking back through the maze corridors.

Finding the Alien Door

Once you have the Alien Key, navigate to the deepest section of the sewer maze. Look for a large, ornate door with an alien-themed design. Interact with the door while the Alien Key is in your inventory to open it.

Inside, you will find a small room with an alien NPC standing near a pedestal.

What Does the Alien Key Unlock?

Opening the alien door reveals the Alien Investor, a special NPC that grants you a permanent +2% cash bonus on every investor you own. This includes:

• Investors you currently hold
• Investors you spend on powers in the future
• Investors gained from all future rebirths

This bonus is permanent and persists through rebirths, evolutions, and ascensions. It is widely considered one of the most valuable upgrades in the entire game because it compounds exponentially as you accumulate more investors.

How the Alien Investor Bonus Works

How to Get an Alien Investor

Many players search for how to get an alien investor in sell lemons. The Alien Investor is not something you purchase or recruit — it is automatically unlocked when you open the alien door with the Alien Key and speak to the alien NPC inside.

Steps to get the Alien Investor:

1. Get the Sewer Key first (7-step lever puzzle)
2. Get the Alien Key (9-step lever puzzle described above)
3. Open the alien door deep in the sewers
4. Interact with the alien NPC to permanently unlock the +2% bonus

For the full lever walkthrough with detailed maze navigation, see our comprehensive UFO Key guide.

Pro Tips for the Alien Key Quest

• Always join a fresh server before starting the lever sequence. Other players may have changed lever positions.
• Use True North as your reference: North is the direction of the hallway with Lime Green Text on the wall.
• Hit respawn after each lever to save time navigating the maze.
• Complete the Sewer Key first — it is simpler and unlocks the Cosmic Cash Vine, which provides ongoing income while you work on the Alien Key.
• Bring friends: The lever puzzle can be completed faster with multiple players each handling a different lever quadrant.

Frequently Asked Questions

Is the Alien Key the same as the UFO Key? Yes, in the Sell Lemons community, these terms are used interchangeably. Both refer to the key that opens the alien room.

Does the Alien Investor bonus reset on rebirth? No. The +2% cash bonus per investor is permanent and carries through all rebirths and evolutions.

Can I get the Alien Key without the Sewer Key? Technically yes, as the lever puzzles are independent. However, the alien door is located deeper in the maze, and having the Sewer Key route memorized helps with navigation.

What badge does the Alien Key give? Opening the alien door grants the Good Samaritan badge, in addition to the permanent cash bonus.