Since there wasn't bombs in classic mode, there wasn't any way of dealing with floating blocks.  Someone had suggested that floating blocks could fall when destroying layers. I decided to try this, but i came into conclusion that it made the game way too easy.   But having this only affect outer layers made this feel more balanced.

• Floating blocks in outer layers now fall down in classic mode (Destroying 5 inner layers will not trigger this effect)
• Fixed some of the blocks getting stuck on side wall when rotating
• Fixed randomness