YMMV / Chimera Beast

• Demonic Spiders:
  • Literal ones in "Reptiles". These come in huge numbers, fire volleys of Spread Shots, and have a very good amount of health. Worse still, they swing about, causing easy Collision Damage. And there's also a giant tortoise to annoy you when you face them.
  • The rockets in "Catastrophe" constitute an instance of Bullet Hell, considering your Eater's large hitbox. They come in large numbers and — once again — shoot an 8-way Spread Shot frequently. If you don't eat them and their shots, your Eater will get overwhelmed.
• Fridge Brilliance: Using your "eat" move on the nuclear reactor boss gives you the "mutation" ability. What can radiation cause in organic creatures, again?
• Good Bad Bugs: It's possible to repeatedly eat the two small, grounded humans without them dying, as long as you bite them at point-blank range. This allows you to get back a lot of health in a level where health food is scarce, as well as getting a good end-of-level bonus.
• Self-Imposed Challenge: Getting the Good Ending in a No-Damage Run / flawless boss fight run. In order to get the Good Ending, you must either die to the final boss and choose not to continue, which can't be done without taking damage, or by timing out the final boss, who has a plethora of very nasty attacks, especially the lightning attack which is a pain to avoid.
• That One Attack: The lightning attack used by the final boss covers the whole screen, has narrow gaps to squeeze in-between and strikes twice. The good news is that it can be weakened by destroying his horns and disabled by destroying both, since they execute the attack.
• That One Boss: The Mini-Boss of the final level, "Catastrophe". You have to fight against a space shuttle, which isn't dangerous in itself- it's pretty large and vulnerable and doesn't even attack. However, it's accompanied by laser bolt drones and the above-mentioned spreadshot-spamming missiles, and the latter will make the fight especially hellish.
• That One Level: The final level, "Catastrophe" contains loads of laser bolts and spreadshot-shooting rockets◊ that will make life hell for your Eater.