Ignore the first digit of the double digit numbers and focus on the second digit.
Easy UFO shooting mini-game
When the UFOs are scrolling sideways, tap in a rhythm starting at 120 beats per minute. As the game speeds up, tap faster. This will allow you to pay more attention to the puzzle that it is paired with.
High scores
Simply play the game with another person and assign each player to their own half of the screen.
Various strategies
Practice the mini-games before trying for a high score. They are limited in number and some are more focused on skill. Focus on completing the mini-games that must be completed faster, then take your time with the longer ones. Solve the easiest games that do not require your full concentration first, then take your time with the others.