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.
That One Boss: Oukumo, Guardian of Gate 99 from Area 3. This boss is a wake up call compared to the first two as it spams bullets along with lasers and mines that can hinder your breathing room from its shots in the first phase. The second phase will have you trying to dodge its arms and the boss itself in the 2.5D plane along with its Frickin' Laser Beams and missile-spamming mines.