I really like this game and the idea of having to change your play style based on the weapon you are using but i can be a little difficult keeping track of then next weapon coming up. Maybe you could increase the time it takes for the weapon to change or make it change only after you have attacked. Kinda like Tetris tells you the next item but does not change it until you have used the current one. You could also add audio queues to signal the player what the next weapon is.