Downward Spiral



Downward Spiral is an Expert Difficulty map in Thermoxin's BTD7.

The map features 4 black lines jetting out of a hole in the cardinal directions. In the hole is a faint 4-armed spiral. There are areas with pieces of metal lying between the lines (which I will add later) that can be removed for $3000 each. On the east and west arms of the spiral are special tiles which you can place towers on.

Bloons enter through any 4 of the lines. They move onto the spiral and move inwards. Upon reaching the end of the spiral, they exit through the same line which they came from.

Now here's the exciting part. At the end of each round, the tiles will rotate 45 degrees clockwise around the spiral, bringing them closer to the center, and a new tile will be generated at the farthest point of each side arm. It takes 8 rotations, or 360 degrees for a tile to reach the center, and when a round ends while a tile is at the center, the tile will fall into the hole, taking any tower on it with it! And starting at round 51, the tiles will start to rotate automatically during the round, totaling 45 degrees and adding an additional 45 degrees every 10 rounds after that.