completed the challenges thus far, hope theres more to come of the tier 2 and 3 buildings! please keep updating this game, after an unseady start i have come to love this game. ps, if you add 2 more buildings to teir 1, it will go 9, 6, 3. just thought it looks nice :) keep up the good work!
Hmm... although the skill tree is a bit sparse, A big update is in the works that'll revamp the skill tree with many new interesting skills!