You can earn experience points by completing your room design tasks and merging high-level items.
Experience points are mergeable, and you can earn more if you merge and collect them from your board.
Once you collect enough experience points, you level up.
You can always check your experience points from the upper-left corner of your game board.
Please click the bar that shows your level to see how many experience points you need to level up.
Learn more about Mergedom: Home Design merge puzzle game.