* CultClassic: An amazing game... but it doesn't have the fame to go along with it. Still, it was good enough to be used as the model for the ''WesternAnimation/AstroBoy'' licensed game.
* FridgeBrilliance: The FinalBoss music is titled "World's Strongest Robot". This both refers to Pluto, as he's the leader of the "World's Strongest Robots"; and [[spoiler:Garon, who the Character List refers to as "the most powerful super robot sent to Earth"]].
* SugarWiki/FunnyMoments: Most of the endgame cutscenes are serious, but the secret post-credits scene offers some levity.
** The BigBad has escaped and is hiding in Fire Vase Island. While he swears to return, [[spoiler:Pook]] points out that they did their best and still couldn't beat Astro, then innocently asks him to consider doing something more manageable, like opening a café.
** The revelation of the BigBad's fate: [[spoiler:He approaches Wato and orders her to become his wife. Puzzled, she notices his third eye, mistakes it for a wound and concludes that he is hallucinating due to a head injury. She then proceeds to bandage it, much to Sharaku's horror, as this seals his powers and makes him docile.]]
* GameBreaker: When maxed out, the Machine Gun special can stunlock every enemy for far too long. Even in Hard mode with a 3 super moves limit you should be able to use it five times in a row.
* NightmareFuel:
** The surprise appearance of [[spoiler:the Death Mask, which proceeds to lay waste to the entirety of robotkind, ''including Astro himself''. The entirety of the game's second half is devoted to figuring out a way to prevent the cataclysm by means of time travel.]]
** Tobio's death. It's brief, but every bit as horrific and gutwrenching as it can be for a parent to watch their child die in such a tragic accident.
* NintendoHard: As in other Treasure games, you get a nice overpowered moveset, but the enemies are relentless. On Hard, enemies will tear about half of your HP with the lightest of attacks, you can have only 3 Supers, and there are MANY things that can kill you in a single hit. What's worse is that there are very few recovery items in each chapter and some of them are supposed to be the level ups that only work once.
* SugarWiki/NoProblemWithLicensedGames: This game was critically acclaimed and is fondly remembered as one of the best action games on the [=GBA=]. Given that it was developed by Creator/{{Treasure}}, which is famous for its high-quality third-person shooter games, this is no surprise.
* TearJerker: The death of Dr. Tenma's son, Tobio; and him grieving for his son as he creates Astro in his image. This is the ''first scene'' in the game.
** The first ending, where [[spoiler:Death Mask arrives and destroys all robots on Earth, including Astro, leaving behind a world completely ravaged by years of war between humans and robots.]]
** Drake is a tragic villain, having been pushed over the edge entirely by the belief that his daughter was kidnapped and killed by a robot, leading to his hatred of robots with him vowing to do everything in his power to avenge her death.
%%** The story of Daichi and Prime Rose. Which becomes even more so when you learn later that the two of them aren't actually gone.
* ThatOneBoss:
** North in Hard Mode, mostly because his first phase basically forces you to waste all three of your Supers.
** Atlas, when fighting him with Dr. Black Jack at the bottom of the map, which leaves you with less space to fight him.
** The jousting duel with Blue Knight, which requires landing a few hits while being a OneHitPointWonder regardless of your life level. Part of this is due to being a GuideDangIt, and another part is due to having to replay a lot of the level if you die.
** Pluto has a sizable variety of incredibly powerful attacks. During Rebirth mode, his already hard-to-predict SpinAttack drags Astro towards him and kills in about two hits.
* TheyWastedAPerfectlyGoodCharacter:
** Princess Sapphire gets very little spotlight, and her romance with [[spoiler:Rock that redeems him]] is only shown through a title screen and a quick line of dialogue with him. She really could have used some extra scenes to develop this further.
** Kimba/Leo the White Lion, one of Tezuka's most famous creations, is reduced to one of Pook's transformations, and doesn't get a character data sheet. On the other hand, one must ask, where else would they have ''put'' him?
* TheUntwist: Blue Knight being [[spoiler:President Rag. The gratuitous flashback makes it screamingly obvious.]]