Changes

The timer defenses disappears by starts from when the defense is placed, no matter what phase it is, so it is recommend to ready-up the stage as quickly as you can on each build phase. If you sell a defense before it disappears, you get the mana back. If the defense disappears due to the timer, you will not get any mana from it. You can still upgrade defenses if you choose to, but the mana may be better saved to build more towers with instead. The increased power and speed make it so that upgrading is not really necessary.