Great
It was very refreshing to play something other than, as you put it, a frantic flying though the air blast-em-up; games like that are overused and usually shallow and poorly done.
This, on the other hand, was fun to play. The multiple types of weapons each with their own stats added a lot of depth to the game, as well as the AI being more than "go towards the player and shoot every .5 seconds."
On the whole, though, the entire game didn't quite seem totally polished; I think it could be a big hit if you polished it up a bit, maybe put in some effects and optimized the engine, and released a sequel.
Anyways, although some people seem to only enjoy midless blast-em-ups, I did appreciate this game and I encourage you to make more like it.