Choose Archer and pump all talent points on Archer passive stat. And always equip agile equipment except when you go on the last quests to obtain shadow gear. With this setup , you will be dishing out 250~270 crit damages with your shadow bow, with a 75% crit chance + 50% dodge chance. Keep health pots handy against last boss. I used 8 pots. Against mobs, pick them off 1-by-1 or 2-by-2.
Game concept is ok. But "too easy". Tip : at the first round - quickly go for control of enemy planet. Eliminate enemy *FIRST*, and then occupy all but 1 planet and just go for lunch or something to build up resources - and then get l337 stats all during round 1. voila.