It took me many more tries that I want to admit (about 20?), as a big part because for some obscure reason during all my runs except for the few last ones I was trying to stay close to the mech while staying far away is much safer in particular when they're drones, rather than trying and failing to destroy them I can safely enough ignore they're here when far enough. Then because it took me this long it was all the more satisfying to finally defeat it, I had fun playing the game.
A caveat would be that I think the sound effects are too sparse (only missiles?) which makes the game a bit less punchy that it could be in my opinion.