The number-based system is easy to understand. Larger values appear through repeated combinations.
The small board creates constant pressure. Every empty space can affect your next decision.
Every successful merge adds to your score. You can keep playing after reaching 2048.
New tiles can appear after moves. Their positions can change your plans.
One movement can create several combinations. A carefully planned move can transform multiple parts of the board.
A new game starts quickly. This makes it easy to test a different strategy after a failed run.