Looking at the images if 25 game, I was prepared to hate it, for being another clone. However, after playing it 6 or 7 times I love it.
1. Combine two 1's to form a single 2. Two 2's form a single 3. Etc.
2. You run out of room when the grid fills up.
3. After each swipe, in any direction, a new tile will emerge, either a 1 or a red tile.
4. Red tiles: this is what makes the game so unique because they're annoying, but also useful.
5. Red tiles will vanish when 3 are lined up.
6. Scoring: There is no significant reward for merging two 9's over two 5's.
Like the game Threes, there is an addictive quality. My high score is 21,573. My highest tile was 11. The game took just about an hour.
What could be better:
1. Threes has better graphics. The part I like most is the ability to swipe very slowly without making a commitment. This lets one see which tiles will merge.
2. There needs to be a leaderboard. If my high score is not in the top 1%, then I'm going to continue to play.
Other Bart Puzzles:
Factory Balls - excellent
Boo! - a mini sequel to Factory Balls
Blocky XMAS - fun and at times hard