The popularity of Block Blast comes from a combination of simplicity, speed, and strategy.
First, the rules are extremely easy to understand. A new player can normally begin playing within seconds. There is no need to memorize complicated combinations, learn a large map, or understand a long list of abilities.
Second, games can be relatively quick. This makes Block Blast suitable for people who want entertainment during a short break. You can play for several minutes without committing to a long gaming session.
Third, the game rewards planning. Although the basic mechanics are simple, achieving a high score requires players to think ahead. You need to consider where the current piece belongs while also thinking about the shapes you may need to place afterward.
Finally, clearing multiple lines can be satisfying. Watching several rows or columns disappear at once gives the player a strong sense of progress and encourages another Block Blast attempt.