# Sliding balls and stars on a 4x4 grid

You are playing a game on the following 4x4 grid. It contains balls, stars, empty cells, walls (solid blue squares) and target cells (T). Each turn you can slide all the balls and all the stars into one of four directions: left, up, right or down. An object will continue sliding along a direction until it hits another object (including walls) or the boundary of the grid. Walls do not move. Can you get the balls to finish on the target cells?

• We now have stars, which move just like the balls, but kind of get in the way. I think this one is quite hard, but I was wrong in the past about these puzzles. Once I have some more time I will hopefully make a mobile game from these puzzles. Mar 17, 2022 at 6:06
• Do the balls stop when they hit a target? And the T at 3 , 2 does not have any type of support, so is it just a diversion from the other one? Mar 17, 2022 at 9:34
• The balls slide through the targets unless there is something to block them on the other side. Mar 17, 2022 at 9:52
• Check out my earlier puzzles on this theme to get a better idea. Mar 17, 2022 at 9:53
• This is my 300th puzzle here :) Mar 17, 2022 at 12:48

The sequence needed to put the balls in their place is:

LURULURDLDRDLURDRULDLURULURDLDRDLULD

I don't have any fancy animation thingy to show my result, but after checking several times on my notebook, I believe it's correct.

Thought process:

To get the balls into position, having all three stars below the balls was needed. To do so, switching the balls from a horizontal position (both on the same row for most of the moves) to a horizontal one (both on the same column for most moves), or separating them altogether, to then slowly pass the stars on the lower part of the puzzle, while the balls take their place in the upper part.

• Cool. How did you come up with that? Mar 17, 2022 at 10:28
• @DmitryKamenetsky Best I can do is provide my horribles notes, but it was mostly trial and error. Along with a lot of thinking. Mar 17, 2022 at 10:47
• Kudos to your efforts! I thought the same logic, but gave up after 10 moves 😂 Mar 19, 2022 at 10:20