Great but so simple game, there are so many things to be done.
- User have to reload everytime to load new level.
- Annoying pop up everytime user wins game.
- Static level difficulty, no change in it.
- No tracking of user wins so on basis of that complexity of level could be increased.
- Control movements are so annoying.
- Tracking of user score, adding multiple complexity.
- Before game start user would be able to select complexity then game would decide based on user performance.
- Random colour changing when win instead of dropping them on ground.
- Including timer challenge.
and maybe a thing or more if I got tyme.