Hi anthony, I appreciate your feedback !
Yes you it may seems little bit confusing (mostly due to 48 hours period), but you get more enjoyment with time to understand the fundamentals !
The game basically is tower defender but you there defending too along with the towers that you build with them, you can build towers on any empty base which indicated buy glowing circle. So the more you progress, the more you build, the more the enemies, the hard ! This is the basic idea :) Good luck.