It's a nice game. But i have a problem with your reward mechanism. I used AdBlocker Plus and deactivated it for this site. I got the message "can't load our adds". Then i activated my AdBlock on another tap and the game showed me a black window without add but gave me the reward. After the last patch the game said even with deactivated and deleted adblock "we can't show you the ad cause of ad block".
With an other adblock programm its the same.
And for the game: I think the step between Black Lich, Flying Squid and Tomb King could be a bit closer. (dunno the people after this)