Stage 30 introduces you to what I believe is the very best powerup in this game. The Fireman makes you completely invincible to your own bomb fire. While this doesn't make you invincible to enemies, it should still be more than enough to clear through them since they just have touch you to kill you, especially with the Remote Bomb since that means you can just blow up a bomb just as you lay it down.
The best part about this powerup is that, even with the music changing after you pick it up, you still get to keep it after completing the stage you got it from. Just don't die from a monster, and you'll stay fireproof for the rest of this run.
This also means you can lay waste to the exit doors as much as you want. Just hold Circle while an explosion is going on, and you'll infinitely chain explosions together, constantly forcing new monsters to come out from the door and instantly get cooked in the process. You can get a ridiculous amount of points this way, and even get several more lives for your trouble, just before you finish this stage.
You're gonna be seeing more of this in the future, just to further show you how this, the Remote Bomb, the Bomb Pass, and the Wall Pass altogether, can turn the rest of this game into a total cakewalk.
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