I have to admit the game feels somewhat... lacking. Can't quite place my finger on it, but the original felt as if it offered more options and more stuff to do even before I bought the extra bits
this is a fun game, but there are some issues that need to be addressed imho:
1. the building/upgrading interface is too large. it's often hidden by the map interface and slows you down. a radial menu over the building site would work much better
2. upgrades would be better off in a corner button instead of a map location. the interface here is also too large, no real need for two pages of them
3. there has to be more time or even a "start waves" button when you first enter a map, new players can get swarmed easily before even building
4. there needs to be a way for the players to see the unit stats, as well as their bonuses
5. find a use for the soldier. after you get Tor, the soldier is useless