A spinoff of the mediocre MOBA, PW:Defenders is a decent enough tower defense game. A handful of maps become "randomized" with obstacles to change your strategy from play to play, but you will ultimately find a balance of towers to suit your play-style. The acquisition of cards/towers being the hardest part, involving lots of grinding and luck to get what you need. The crafting system is poorly explained, but with a little trial and error it can be figured out. Or look to the forums and guides to tell you the two important things the game doesn't tell you.
What killed the game for me is the constant bugs and sudden loss of data. Towers don't always hit their mark, bonuses are either not correctly applied or explained incorrectly, daily rewards and store offers disappear/reappear randomly, and achievements will stop functioning after a certain level. This prevents any further progress through Steam's system, though they can still be earned in game. Not long after losing the ability to gain Steam achievements my data was completely lost with no hope of recovery. Still not sure how that happened, probably an error on their server regarding saves.
Looking to the forums shows absolutely no further dev interaction, patches, or support. This is essentially dead software. If you are hoping for patches or fixes, either the community will have to find a work around, or you're ♥♥♥♥ outta luck. I bought this on sale for $2.00, and certainly got my money's worth out of it. Even if I didn't complete it. But at current full price of $10, it is definitely not worth it at all.