Extremely new major update of public demo - v5a.220723.

The Boss is here! And a lot of new stuff!

• Added the final boss, the Dragon. The map now generates Ruins - an object that is always a single copy, and it is located in a random place each time. At the end of the last wave timer, all surviving creeps are killed and their "souls" are carried inside the Ruins, filling the Dragon with additional lives. After that, the Dragon appears near the Ruins. To win, the player must kill the Dragon before the round timer expires (the same amount of time is allotted to kill the Dragon as a normal round). So far, the Dragon has a small amount of health at the start, but this is his first appearance and it will change.
• Added [Special] construction - Pillar of Power. Each race will be have one unique special building with some effect or possibility for other towers. Special construction is NON COMBAT, it can't attack creeps. First of this building is "Pillar of Power" - it increase maximum damage of nearest towers by 25. Of course, it's costs expensive, but useful.
• Added WASD movement for the in-game camera.
• Added limits for crystal mines. Yes, there are all mines have limit of crystals in it now.
• Conversion prices have changed.
• Minor text changes.
• Major balance changes.  It's getting hard to play even for me!