Enjoyable at first, but frustrating & unforgiving. Once the 4 skill trees are filled what point is there to continue? No other skills appear to make the increasing difficulty of each level bearable. 1st few levels "oh yeah I wouldn't mind spending a few bucks money on this", to a few days later "heck no, screw this". I'm not busting my new Galaxy Fold in frustration with this, as each playthrough I feel like tossing it against the wall.