I read the instruction "Don't shoot the barrier" and of course immediately shot the barrier. :)
It's a cool game, the definition of small and polished. The visuals are nice, the controls responsive and intuitive and the sound effects are well chosen. The game gets really tense when you get swarmed by enemies, because panic spamming will only make you lose faster. I think it was a good choice to have the barrier "reset" when you level up, it feels way more forgiving like that. I had a lot of fun playing!