Pretty decent. Got bored around when the martians show up, though. Upgrades start taking long enough to come that I get bored. A minuscule increase to one of a ton of stats every 2-3 minutes...meh. Up until then, pretty okay though.
Really wish badges of the day would stop leaning so much towards "Beat the entire game." Fun for the first tennish levels and then they start getting so long I just find myself constantly checking what time it is.
Devs really aren't helping themselves constantly broadcasting the useless junk you always get out of key boxes while at the same time showing off the awesome stuff you can get for free. Buff the loot boxes and maybe people will spend on them.
Every few months the reward for a weekly challenge is an item from here and I return, having forgotten what this game is. 30 seconds later I run out of energy, not returning until the next challenge.
Thought process of a survivor thinking about joining you: "Hm, they've got lots of food, some nice defenses and they're happy. Maybe I'll join them-wait! Those outhouses don't look quite comfy enough for my sensitive bum. Maybe if they upgrade 'em I'll take another look. For now, back to my cardboard box."
Would be a fun game if the enemy didn't always seem to have some magical crit powers while I miss 40% of the time. Happening on occasion I can understand but it's a constant, every fight thing and people in the chatbox notice it as well. I like spending a little money on this kind of game, but when I do it's to gain an advantage, not try to even myself up on a biased system.
Fear not fellow challenge hunters! You do go all the way through the game, but I did it in about ten minutes, only spending money on the last lvl and, iirc, 27