Final update for the game

Finally, I can consider the game finished!

Updated the climbing controls: A, D to move left & right and W, S to move up & down. The previous version was A & D for going forward & backward on all surfaces.

Added tutorial levels & balanced the game: Player used to have too much health. Now the Axie is more vulnerable. But I have also reduced the damage from the spikes. You can make a few jumpy mistakes and survive.

No more slippery corners: The corners used to be slippery, so I fixed them all.

Harder boss fight: No more staying in one place firing at the boss with Dragon mode. You now have to move around and use other tactics.

There may still be some other bugs. But that's it for now. I'm moving on to my next game!