There are 50 levels in the game, so you can play it for many hours. When you have completed the first 15-20 levels, you will have to think many steps forward to advance further. Then it slowly becomes harder and harder.
The first 5-6 levels are fairly easy, and won’t take a lot of time. To do this, you are in control of a little man, who can walk and push. There are a lot of crates that need to be pushed to the right spaces. There is everything from online java versions, to bigger games like Docker Sokoban. If you google it, you will get about 150.000 results. In the years from the development of this game until today, a lot of Sokoban clones have been made. It is not only one of the first it is also one of the best. The Japanese company Spectrum Holobyte developed it in 1984, so it already had its 20 years anniversary. I think Sokoban is one of the first puzzle games ever made.