The Castle (SG-1000)

This game's a port of an MSX game, but I'm writing about this version because it's the one I discovered first and because I really like the SG-1000's colour palette.
It's a very old-fashioned platform adventure game of the sort that were popular on various computers in Europe in the 1980s, (l'Abbaye des Morts by Locomalito is a pretty great modern-day tribute to the genre) so much so, that I actually tried to find an "original" C64 or Spectrum version from which the SG-1000 and

MSX versions might have been ported, until I saw the MSX version's title screen, which credits the game's original authors, Isao Yoshida and Keisuke Iwakura.
Anyway, the plot of the game is a generic "save the princess from the castle"-type affair, and to do so, you have to find your way around the 100 room castle. Unlike most modern metrovania games (which could be seen as the spiritual descendents of this genre), combat is far from the player's main concern in this game. Keys are the most important thing, available in various different colours, to open doors of matching colours. There's also potions to increase your number of lives, and various kinds of treasure to increase your score. The meat of the game is working out how to reach each item and each exit in every room without getting killed by any of the enemies or traps in the room. There's items that can be pushed around, like bricks and vases and such, though they all act the same. they can be jumped on top of or pushed from the sides, and they fall off of platforms. They're also your only weapon against the enemies in the castle, as pushing one of these items into an enemy kills the enemy. Dead enemies stay dead, even after leaving a room and re-entering, while items return to their original positions, meaning that a single item can be used in more than

one part of a room, as long as you exit and re-enter.
The controls are obviously simple: the d-pad moves your character, one button jumps and the other, unusually, changes the speed of the game, allowing the player to switch at will between full and half-speed, depending on whether they're waiting for an elevator to come down to them, or timing a risky jump over an enemy's head.
There's not much more to be said abou this game, other than that it meets my approval. It's a lot of fun to play, and it's neither brutally hard nor insultingly easy, and solving each room feels like a satisfying little victory.