Ideas for Making Games Great

• Create an interesting user interface that still remains functional
• Integrate a hint system so player doesn't get frustrated
• Diversify the gameplay to keep the player interested.
• Avoid repetitive tedious tasks. 
• Integrate High score memory to keep the player playing. 
• Have "Fun" scores that aren't just intervals of 1
• Interesting Color palette
• Interesting and Satisfying sounds
• Give the user gratification or progression for playing.