Played it for a couple of hours last night (apparently that unlocking thing isn't really true, since you get to play the "beta" which as far as I can tell just doesn't give you achievements like normal...even though it seems to have recorded that I finished all of them, just hasn't actually given me them yet) and it is decent. It reminds me a lot of the flash games like Gemcraft and Kingdom Rush, just slightly different. The major difference, however, is that you have to win/buy cards in order to level up your existing ones and get new ones. Fortunately you buy them with the stars that you earn from completing the missions (think Angry Birds with 1, 2, or 3 stars per level) and not a Pay2Win model. You can also earn "coins" that do things like allowing you to buy powerups, or upgrade your cards, etc. Very early on (beat the first "boss") it seems to me like my coins are always going to be in short supply and SorrowsEnd's comment of it getting grindy is probably dead on. Unless coin rewards get a lot bigger I'm never going to have the money to upgrade all of my cards (which will probably also involve me buying some "artifact" cards which give XP to your cards to level them up (enhancing), which is different than evolving them).
I don't really mind a "grindy" tower defense game since I've played tons of them and still am working on gold-medaling challenge modes on Defense Grid, so I'll probably be fine with this game. I can't say I know how it will be later on, but if that isn't something you look forward to, you might have trouble finishing this one. Particularly since it seems like there aren't that many different level layouts. I've seen the same 3 or 4 several times already, they just rotate the stupid thing so you're looking at it from a different perspective (and I haven't found any way of rotating it myself). Maybe more will show up later, but already repeating levels several times on the actual storyline missions seems a little lame. You can "raid" around a boss which is basically just randomized missions to earn coins, stars, and cards (random reward) so I'd expect those to be repeated levels, but not storyline missions. Even free flash games typically had a different layout for each one, because levels really aren't that hard to make.
Oh, and none of the levels I've encountered yet have been very complicated. There's one that is essentially a spiral, and one that has a straight shot to the "cores" if you don't block some paths, but there's nothing like Defense Grid where you have to look at the fucking thing for 10 minutes trying to figure out your best layout. There's something to be said for this simplicity of course, but when the levels are repeated that's kind of a negative I feel.
I'm making it sound horrible I know, and it isn't. There are your typical card game highlights like pulling a rare card and getting to use that rare tower the first time. Like, you get a standard poison tower for free, but when I bought some "packs" I pulled a Serpent Tower which does a poison cone that affects multiple targets and looks like a big hooded cobra. It's almost twice the cost of the regular poison tower, but it absolutely destroys the swarm waves of weak creatures. Of course now I have to try to pull two more to max evolve it, and level it up...but do I level up my other, cheaper towers first? So yeah, it is probably going to be a grind, and I'm probably going to get sick of seeing the same levels, but there are a few carrots along the way. Hopefully those are enough.
