Is this ok?

[fengsp]

Doing something like 2048 is not good already, what you are doing here is totally one copy of the original work. The problem here is that Threes is one commercial product, you go even far more than 2048(one varietal copy) did.

I really do not think what you are doing is right. If you just want to practice your programming skills, please make this repository private. Making this public is kind of illegal. Of course, if you have got the permission from the original authors of the Threes, that would be no problem.

Sorry, but I still think you need to know this. Copyright and license are there for a reason.