Quest

Every slide moves every tile. Two equal tiles merge once. A new tile comes after each slide.

Unlocks 5×5 in free play

Not the most merges: the merge that builds toward your big tile. Line up the tiles next to it first.

Unlocks Medium in free play

Keep your biggest tile in one corner. Slide toward it; the tiles grow next to it.

Two directions are not always enough. Use a third only when the big tile's row or column is full, so it cannot move.

Unlocks Hard in free play

Chapter 4's lesson again, at 512.

When the big tile is out of its corner, bring it back before you build.

Unlocks Expert in free play

Everything so far, up to 1024: keep the big tile in its corner, and use a third direction only when its row or column is full.