I suggested in the chat too potential future add-on that will make this game better.
1. Allow you to duel your friends (a Live duel would be best but I would settle for an offline version too)
2. Save a fight progress especially on the mobile app. I have had several times where I am in the middle of a duel and I get phone call or accidently hit the home button and I am booted out of a duel, lose the energy and get no exp reward. The option to continue an ongoing battle when you relaunch the app would be great.
I would have liked this game a lot more if by level 20 the game was for all intensive purposes over because nothing left to find or buy, once you have all the god mode armor pieces (completed set by level 20). After that no sense in playing further.
Well, it was worth the one time play but 2 big concerns first the poison gun cost way much more to upgrade then any other gun. And I beat it first try and no skill or planning involved just piled a bunch of towers at the corner. Also the amount of money you get per kill seems kind of lacking mainly because I could never get to the point of upgrading my gun to the 700 level at 2-4 $ a kill you never got enough chance to make it to 700 before you had to build more towers.
Press D to select buildings of the same type as the one you mouse-overed on. Then press E. Simple!