I like that you get time bonuses for shooting the targets. Initially, it is hard to discern which targets grant bonuses as they have the same primary colour. It may be easier to have completely different colour for detrimental targets. The large bonus target in the far back is extremely useful.
It was tricky at the start, as the timer starts the moment you load instead of when you shoot the black square. It may be better to start the timer once you shoot the black square. The large and steady flow of targets really helps in chaining together targets in order to stay alive.
A fun warioware-esque gallery shooter.