You might want to play the Gameboy Kid Icarus. It’s mostly the same with a few subtle improvements: Instead of helper angels you just get items from breaking the statues, which makes the fortress parts more endurable.

I replayed Metroid a few years ago and while it’s more primitive compared to the later games, there’s something cool about being able to customize the experience by doing things in a different order. You even need to master bomb jumping just to find Ridley with the Wave Beam.

You’re not missing much with the original Metroid II. Either the 3DS remake Samus Returns or the unofficial AM2R is better.

<I>Is this the first time that a video game ominously referenced its predecessors and winked all-meta at its audience? Can anyone find anything like this predating 1994?</i>

Wonder Boy III: The Dragon’s Trap begins in the same location as Wonder Boy II ended. This is really interesting because Wonder Boy II is a very linear arcade game while Dragon’s Trap is a full-blown Metroid-type adventure.

Dragon Quest III contains the entire first game’s overworld (without spoiling too much).