How to play well
The rules take a minute. What separates a two-minute game from a twenty-minute one is the order you take tiles in.
Step 1 — clear the top
Start with the highest layer: those tiles cover the most. It matters little which pairs you find, as long as the surface comes off.
Step 2 — work from the edges
Edge tiles are almost always open on one side. Move around the perimeter towards the centre and you will not build a block in the middle.
Step 3 — remember blocked pairs
When you see two matching tiles and one is locked, keep them in mind. The pair becomes available the moment the lock goes.
Step 4 — shuffle without guilt
Shuffling costs nothing: the board stays solvable and the clock does not jump. It beats staring at the same arrangement for five minutes.
Step 5 — count the moves
Good players watch the number of possible pairs, not the tiles. When it drops to two or three, shuffle first and think later.