v0.13 - Spires!

v0.13 introduces a new building concept: Spires.

Spires can be built to antagonize the aliens, making them spawn faster or in bigger quantities.

Respectively, they reward people who want to take risks or simply want more challenge.

1. The Provocation Spire allows you to end the wave earlier, letting you construct the bomb faster.
2. The Aggression Spire gives you more loot!

I wanted to add this as it speeds up the game loop, making it tighter!

Let me know if you try them out~

-YYZ