Just started this game today. Pretty cool concept! I've noticed that if I suck enough in somebody's dungeon, the game disables one of the defenses for me to let me win. I don't really like this feature, because it makes me feel like setting up a really tricky defense is a fruitless endeavor. We have to beat our own setups twice in a row in order to save it, so it's not like we can put up impossible defenses. They should make it to where players cannot steal a gem if they die enough to get a trap disabled.
The chance of your gem being stolen is very rare, but it will happen eventually, I assure you. People that sink money into the game and use the best characters will get you eventually.
I just started today (level 4 now) and just raided a guy and got a gem worth 1.4k in that slim chance after dying enough to get a defense disabled. Sure, it was good for me, but it just doesn't feel right.
I just started playing this game about 20 minutes ago and I definitely agree with this. It's cool, but almost makes me feel cheap and how it will make it easier for someone to eventually steal MY gems too >.< I'm REALLY enjoying this game otherwise though! Reminds me of a simpler Super Meat Boy.
In This case the freemium nature comes in The way ruining a Game otherwise great. Timer for keys let you play too short sessions, like last angry birds games. 3 stars because is a great missed opportunity.