What do the beam colors do?

Yellow breaks rocks and robots, cyan lets you push, red opens red energy doors, green lets you walk through walls, orange jumps two tiles, and purple (West 2) carries you to the beam's far end. You get a color's power by standing in its beam, and two beams at once give both powers.

Do gems redirect the beams?

No. Beams come from fixed emitter blocks. A gem placed in a socket switches on every emitter in that room; take the gem back and they go dark.

How do you move a beam emitter?

Often you don't need to - moving a gem to another room's socket changes which beams are lit. Emitters themselves can be pushed; stand in the cyan beam to push blocks, and check the map first because beams run across the map's edges.

Am I soft-locked while collecting gems?

Probably not if the Gems counter dropped - it shows the gems you carry, not your total, and placing gems in sockets lowers it. Check whether you moved a room's gem elsewhere. Real soft-locks are reported by players (no pushable object can reach the last gem); undo back past the mistake, and reset only as a last resort.

Where are the West solutions for the full game?

On the Vault of the Beamcasters page (West 1 and West 2). The demo's 20 gems from The Promise are listed separately on the West gem reference.

Order of the Sinking Star Explorer Guide: Gems & Beams (West)

Who the Explorer is

The Explorer is the West protagonist, working through the underground caverns of Vault of the Beamcasters (called The Promise in the demo). Their puzzles run on colored light beams fired by emitter blocks, which you switch on by placing gems in sockets. The West has two big open sub-areas, West 1 and West 2, where you collect gems in almost any order.

A beam crossing the sky in Beamcasters · Screenshot: Thekla, Inc. (Steam)

Beam colors

Beam	Power
Yellow	Break boulders, rocks and moving robots
Cyan (blue-green)	Push things; without it you cannot push at all
Red	Open red energy doors
Green	Walk through walls
Orange	Jump two tiles in any direction (not onto a wall)
Purple (West 2)	Step along the beam and you travel to its far end

Beams stack. Stand in two at once and you get both powers: orange plus yellow breaks things two tiles away, and two orange beams let you jump four tiles.

How gems and emitters work

Beams come from emitters: colored triangle blocks that always fire in one fixed direction.
Gems are the power. Each gem is a blue orb. Put it in a cross-shaped socket and every emitter in that room lights up; take it back (the same key) and they go dark.
Standing in a beam grants that color’s power.
Two layers: the surface and darker depths below. Press Tab for the map, a 4×4 grid of blocks.
Relics. In the West 1 depths you find a wand that moves the thing in front of you one tile forward; in the West 2 depths, a necklace that turns a beam to face the way you are facing.
The Gems number in the top-right corner is the number of gems you are carrying, not your total progress. It drops whenever you place one.

How to move a beam emitter

Try moving a gem first. Putting a gem in a different room’s socket changes which beams are lit, which is often what you actually need.
Emitters can be pushed. Stand in the cyan beam to push blocks; in Joric’s demo run a red emitter is shifted next to a cyan one near the end (29:05–31:20).
Check the map before pushing. The map wraps around, so a beam can run off one edge and come back on the other. A push can change rooms you are not looking at.

Am I soft-locked?

A falling Gems counter is normal. It only counts the gems you carry; placing gems in sockets lowers it.
A dark beam usually means a missing gem. Check whether you took that room’s gem to use somewhere else.
The 12-socket array is not a dead end. In the demo’s depths, 12 gems light a red beam; in the video they are all taken back afterwards (20:24–20:54).
Real soft-locks do happen, according to players: no object you can push can reach the last gem, or an emitter has been pushed into a corner. Undo back past the mistake (players report undo on Z, and holding it rewinds many moves); reset the level only as a last resort, since players report that a reset clears the gems you have collected.

Two things to know before you start

You can soft-lock yourself. A clever trick can quietly make the rest of the area unsolvable, and players report playing on for fifteen to thirty minutes before noticing. See Am I soft-locked? above.
The intended solutions are usually simpler than the trick you found. If your plan needs an exotic maneuver, you have probably missed a plain one.

West solutions

Every West 1 and West 2 gem in the full game is solved on Vault of the Beamcasters. The beams also meet the other worlds in crossovers such as Reflected Beams, Stones Illuminated and Heroes and Light, and later in High Beamcasters and Low Beamcasters. If you played the demo, its 20 gems are listed on the West gem reference.