7/10 game. I experienced several times being unable to draw lines to properly defend myself against enemies high up (especially the balloon fights), too few upgrades/too cheap compared to how much gold you can amass (I had around 7000 gold when I completed the game, probably enough to buy all the upgrades all over again). I honestly didn't care at all about stone wall, or any of the others. Only spells I had any real use of was heal, fireball and freeze. I used Bubble wall once, but that was pretty much it, and stone wall was only used by accident. As others have mentioned, I missed upgrades that would actually matter, i.e. make the walls I created last longer, be longer etc etc
Best TD I've played ever. I think it says something when I've been playing 6+ hours straight, and I'm not even bored of the farming. (Holy shit at the price for *Evni*)
 "Wizard Walls"){kind=icon}
 "Neon Race 2"){kind=icon}
 "Defender's Quest (lengthy!) Demo"){kind=icon}