YMMV: Robotrek

  • Breather Boss: Bug Bug, both times.
  • Demonic Spiders: If you ever run into an invisible enemy, prepare for pain.
  • Game Breaker: One item, creatable from about the game's mid-point, is a backpack that heals your robot each turn. Get it, and max the bot's Defense, and losing becomes basically impossible.
  • Goddamn Bats: Mole enemies in the volcano level. They randomly hide in the ground, making them invulnerable for that turn, have a screen-wide earthquake attack that not only damages you but destroys capsules, and use a melee attack designed to hit your back.
  • That One Attack: Confusion. Any enemy that can use it can lock you in a near-endless cycle of uncontrolled movement unless you save against it, which even a fully-upgraded robot cannot do reliably.
  • That One Boss: Being an Enix game, the list of bosses that aren't in this category is smaller.
    • Meta Crab: A Wake-Up Call Boss, if anything. Long-range attacks don't work on him, even the easily spammable big-bang attack.
    • Mamurana: Not only does she do moderate damage, but she constantly splits into clones.
    • Big Eye: He hurts. A lot. If you wasted your Scrap 9 on something other than Shield 4, this is effectively a stopping point in the game until grinding overtakes his power.
    • Black Tank: Continues the trend that Big Eye started.
    • DeRose: The poster child for this trope. She has the most HP in the game aside from the final boss (About 5000), a confusing laser attack, a powerful nuke attack, and essentially an instant death melee attack. It's also impossible to do more than Scratch Damage unless Axe 3 is used with the triple hit combo, and all three have to hit. The fight is trying to hurt her faster than she can deplete your stock of Cures.