These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Game Breaker: 1 lets you have both the piercing bombs and the remote bombs at the same time, making it very easy to clear levels quickly. Every level also starts with a ridiculous amount of Mercy Invincibility, so it's very easy to clear out most of the enemies in a stage before you can even take a hit.