The aim is to select numbers that sum to 17. You can select numbers by clicking and dragging across the grid, and once your selected numbers add up to 17 let go to use them up.
Your score is defined by the product of your selection and how many numbers you have left when the timer runs out, so try and use as many numbers as possible in one go and get rid of the zeros with low scoring numbers.
My best is: 3907 points playing at a difficulty level of 1.
111 points playing at a difficulty level of 25 (the hardest)
This project is so nearly a 1sprite1script project, but requires only a single custom block for the "run without screen refresh" option. Please visit http://scratch.mit.edu/discuss/topic/47675/ if you want to help in fixing this problem.