Glowdrop Lab

A glass only takes liquid when it has free space and is empty or shows the same top color as the glass you picked. A glass already full of one color is finished, so it can neither take nor give liquid. Tapping another glass that still has mixed colors simply makes it your new pick.

Every pour is one move, however many layers flow. Pouring three matching layers at once costs the same single move as pouring one, so moving whole stacks keeps the count low. Undo takes the move back off the counter, and Restart sets it to 0.

Solve the puzzle in no more moves than the level's target, which the win screen shows. Finishing up to 5 moves over the target earns 2 stars, and any finish earns at least 1. Targets come from a checked solution for each board, from 3 moves on level 1 to 18 on the longest puzzles.

Hint lights up two glasses and names the pour, for example glass 2 into glass 4. It reads your current board, so it helps after any number of moves, and it is free with no limit. If the board can no longer be solved, Hint says so, and Undo or Restart puts you back on track.

Yes, a board can run out of legal pours, but you never lose a puzzle. The game tells you when no pours are left and makes Undo glow, so you can step back as many pours as you need or restart the level from its first layout.

Each puzzle has 2 to 7 colors and always two more glasses than colors. Levels 1–5 use 2 colors in 4 glasses, a new color joins every five levels, and levels 26–36 use all 7 colors in 9 glasses. Every color also carries its own symbol, such as a circle, triangle or star, so colors are easy to tell apart.

Level 36, the last puzzle of the Moonlit Lab collection, ends the game. From the level list you can replay any of the 36 puzzles to improve your stars; the list shows your best stars for each level and your total out of 108.