Too Easy
Any nothing changes after you get given the last weapon.. pretty much just stuck to the blue rockets and then spammed them, used the fast machine gun while they reloaded and jumped about collecting the numerous health packs. Only needed to use force field and proton gun thing for the boss and then it was less need and more a case of might as well use them.
Reminded me of the invincible tank game which I enjoyed because it was a new idea.. but then just wished this was as good as that was...
Though still a good game.