it's more than just annoying that over 50% of the levels even on middle difficulty start with a "you lost". at least it felt like it were more than half the time. You definitively should change that.
And it's really bad (at least in my mind) that the tanks start driving as soon as a line is cleared. I mean .. if i simply place tags everywhere on a line the tank starts. these are not really smart drivers right ? but ok, filling a whole line with tags is not what people normally do. To keep it more realistic: i came to a point where it was unclear where to place the last few mines. to figure it out i simply started to place them to see at what point the math would work. and suddenly one of the tank starts and i couldn't stop it. If they start driving by themselves right after a line is finished, they also should go back if a tile on the line is removed again.