This is a nice twist on the sokoban mechanic. The "YES" and "NO" messages are fun in the beggining when you are still confused to what is happening. But at the later levels it gets really annoying to get a message and annoying sound each time you make a wrong move and try to think.
Many levels are well designed and feel really rewarding to solve. However, some of the levels are late in the game, yet very easy, almost like I found unintended solutions...
All in all, good job. Nice Game!