Thanks for playing my game!
As for the effect of killing enemies, at the moment there are 3 types of enemies, where one of them is kamikadze bombers, who after a certain time blow themselves up, trying together with you :), so when the screen shakes, it's because the kamikadze bomber blew up), I hope now it's a little clearer.
There are 9 levels. I agree that it's hard to get to them through a wizard army, so you're may bound to lose a few times), it all depends on randommess and skill. You're a mortal, not a wizard ;)
If you liked some of levels, maybe you would like the next ones too, so suddenly what, I recommend :).