Damn, those are some unforgiving bomb ranges!
I kept getting myself stuck, and then anxiously-doing-a-mad-dash-to-get-as-far-the-hell-away-as-I-possibly-can before just about getting caught in the blast and dying anyway!
I think you should keep the non-grid based movement, and the bomb-blasts being so massive makes me really fear bombs more than anything I have ever experienced!