I like the game, lots of potential, but you simply need extra features A.E. Storyline, would be a good thing, larger landscape, and able to add extra units.
To win Seriously Hard or Impossible-
Win the game on Easy. Then, send 5 survivors to school and fully upgrade EVERY skill. THen, start new game with these 5 surivors.
(play the game right the secind time through- no skips on gameplay)
Thank you for rating 5 stars! Glad you love it. :D