Lvl 20 requires some luck, granted, and becomes much easier if you get good drops but compared to other strategy games it is far from impossible. Have you got a high range upgrade? Maxed the auto-kill skill? Worked out a good order for capturing buildings? Got a decent amount of xp/levels? If not (with the best will in the world) stop bitching!
For me a brilliant Lvl20 just required a few restarts until I got lucky with gold/mana drops and freezing/insta-kills/fear. My build was 6 towers at the start along with the mana well > Lighthouses > Ships > More towers. Having the caves upgraded to fire 5 undead charges was also very iseful on that level. Hope this helps!
While I appreciate the new ability to sell old upgrades, the ridiculously low replay earning doesn't make this a fun and challenging game - just a grind. Got the medals, won't be back.
Such a massive shame... I absolutely love this game - I'd happily pay for it on steam - but the constant money grabbing just ruins it and there's more than any other game like this I've played. 0/5
I really didn't mind the frames platformer - and contrary to what so many people are saying it /can/ be solved with logic. Not finished yet, but so far... 4/5