1. Refraction
Mirrors can turn laser beams by 90 degrees. You just need to move the mirror to direct the laser into the target. You really aren't supposed to get stuck on this one.
2. Curl
You can rotate pieces by using the same keys you use to turn your party. You uh, aren't supposed to have trouble with this one either.
3. Symmetry
Mirrors are double-sided.
4. Loop
This puzzle is pretty similar to the last one. Remember, mirrors are double-sided.
5. Mouse
This puzzle introduces walls, which block lasers. And also block everything else. Look for the path to the target that requires the fewest turns.
6. Three
This puzzle introduces a three-pronged splitter piece, which can split a laser beam into two beams if rotated correctly. You can split a beam and then split the splitted beams again, the beams don't lose power or anything.
7. Spread
You'll need to make a long chain of beam splits here. Each split should use one beam to hit a target, and the other beam to hit another splitter. The last splitter is an exception and will need to hit two targets.
8. Starlight
There are just enough mirrors to hit all the targets; you can't waste a single one. Start by hitting two of the targets in the four-pillar cluster.
9. Reflection
This puzzle introduces a mirror that reflects incoming beams right back into themselves. This is not useless.
10. Colour
This puzzle introduces colour. I didn't need to tell you that. Coloured targets must be hit with a beam of their colour, and only a beam of their colour; a blue target must be hit only by a blue beam, and a magenta target must be hit by both red and blue, but not green.
11. Mix
This puzzle is just there to beat colour mixing into you, in case you didn't notice it in the previous level. A cyan target must be hit by both blue and green; a magenta target must be hit by both red and blue.
12. Merge
The splitter can be used to split a beam, but it can also be used in reverse.
13. Wire
The last four levels were really easy to introduce new mechanics. This one is an actual challenge again. You'll need to use the splitters for both splitting and merging.
The two mirrors should both be placed in the center column, one on each side of the green targets.
14. Prism
This puzzle introduces the prism piece. When a beam enters from the clear side of a prism, any red in that beam will come out the red side of the prism, blue will come out the blue side of the prism, and green will come out of the green side of the prism.
This is symmetrical: red that goes into the red side of a prism will come out the clear side, and other colours that go into the red side will just stop there.
15. Coupling
Separate the white beam using the prism first, then split the green beam with the splitter.
16. Seven
You don't have any mirrors, but you can use prisms as mirrors for red and blue beams, and you can also use prisms to block out colours you don't want.
17. Correction
The mirror should be in the center of the level.
18. Bidirectional
Prisms can't be used to change the direction of green beams. Despite this, only one of the mirrors is needed for the green beam.
19. Flower
Note that the targets are already lined up by colour; you don't need to put anything in the center.
20. Bleach
You can use the same splitter to both split and combine.
21. Secondary
After separating the white beam into red/green/blue and combining two of them into yellow/magenta/cyan, you can split that secondary colour and reuse its colours to create the other two secondary colours.
Remember that you don't need to use a prism to combine two beams: you can also just direct the beams into each other.
Use a prism to make magenta, then another prism to split the magenta beam. If you do this in the right direction, it will set you up well for making yellow and cyan.
22. Backscatter
Revisit level 9, "Reflection", if you're having trouble with this one.
23. Intersection
Every target on this level needs to be hit with green, and prisms can't change the course of a green beam, so there are only a couple of ways you could place the mirrors.
24. Reduction
Probably my favourite level. Did I mention that mirrors are double-sided?
25. Filter
This puzzle introduces filters, which limit which colours can pass through them. If you're playing the Mac version (or using the OpenGL renderer on Windows), emissive colour doesn't work with modulative blending, and as a result the filters will appear almost entirely black with only faint specks of their actual colour (from the particle effects) - sorry!
Anyway, you want to split the white beam before using any mirrors.
26. Absence
This puzzle introduces movable filters...okay, not that exciting. Because the filters are secondary colours, they'll only filter out a single primary colour each, and you need to filter out two primary colours for each target.
Start by splitting the white beam. Put one of the split beams through one of the filters, then split it again, so you'll have two beams of the same secondary colour, and one white beam. You'll need to use the remaining two filters twice each to turn these into the three primary colours.
27. Reuse
This is like an easier version of the last puzzle. Not sure why I put it after it. Let alone right after it. Start by splitting the white beam. You'll need to use both filters twice.
28. Convert
This puzzle introduces the converter, which changes colours to other colours. Its rotation determines whether it cycles red -> green -> blue or red -> blue -> green; the colours on top of the converter indicate which colours will come out for each colour that comes in.
29. Pair
Because there are only two converters, you'll need to use long snaky green beam to hit all of the green targets.
30. Roundabout
First figure out how to make magenta with just blue, a converter, and a prism. Then you can worry about getting the red target too.
31. Blues
The position of the blue and red targets should give you an idea of where to put the prism.
The prism belongs directly between the blue and red targets.
32. Infinity
Remember, splitters can both split and merge.
33. Asymmetry
I don't remember why I decided to include this puzzle, it's pretty dull. Split the green beam.
Don't combine the blue or red beam with the green beam, you need them for the magenta targets.
34. Return
This is where things get hard. You know by now that the non-diagonal mirror will be used with a splitter. Think about how you can use that to get all these secondary colours.
35. Morass
This is easily the worst level, and annoying to navigate, and I really should have gone to the effort of replacing it with something better. Sorry.
So why did I add it in the first place? I liked the central gimmick of it: you start with the right coloured beams for the targets, but can't actually reach the targets with them, so you have to break the beams up.
Instead of disassembling and re-assembling the two beams separately, use the green from the cyan with the blue from the magenta, and the red from the magenta with the blue from the cyan. This requires fewer mirrors.
36. Cycle
You only have four pieces that can actually change the path of a beam - the rest "just" change the colour - so it should be pretty clear where to put them.
Then think about the one place the filter can be.
37. Rotation
This puzzle introduces the rotator, which rotates all incoming beams clockwise or counterclockwise (indicated by the spinning particles on top). I added this piece and a few levels to give players a break from the rather over-demanding converter and prism levels.
Rotators are special because they are thoroughly asymmetrical. Reflecting a beam back into one always does something.
38. Forthscatter
The locations for the rotators should be easy to figure out, but you need to be careful about where you put the clockwise ones and the counterclockwise ones.
39. Clock
You can hit the same rotator more than once!
40. Weave
Green needs to go everywhere, but red needs to only go in certain spots. Think about how you can combine the prism, the splitter, and that one mirror. Sorry, I really can't think of a good hint for this one.
41. Tumble
Kind of a calm before the storm situation, here. You're not gonna like the next level if you needed help with this one. That said, start by using the prism to divide up the white beam before it reaches the white target - really!
42. Finale
You need to squeeze all three secondary colours out of one red beam and one converter. This means you will have a beam that follows a very long and complex path.
You need a loop to even get started making more colours, so make one out of the four splitters. You did beat level 32, "Infinity", right?
Positioning the filter correctly with the converter will get you up to two secondary colours.
With the four splitters arranged correctly, the mirror can be used to create a second loop.
You need the filter, converter, prism, and mirror all in fairly specific places to get the correct colours to the correct targets. You could do this with trial and error, but before you resort to that: think about how two of the targets are the same colour, and what that tells you about where you should put these pieces.