It may suprise that covering of the The Day series starts with part 2, but there's a reason for that. Mirinae had planned and advertised an MSX the first episode in 1989, but it was never released. However, although they dropped the entire first game, the number for the sequel stayed, to much confusion for later retro gamers.
The game itself is a sidescrolling shoot 'em up, and a pretty good one at that. It doesn't need to fear comparison with highlits by the big names on the MSX2, like Compile or Konami. Extensive story cutscenes, big enemies and fluently scrolling stages - the game delivers everything an MSX2 shmup fan could ask for. There's only a few technical weaknesses, so the status bar is only visible when the game is paused, and there's some noticeable slowdown during the second level. The music also isn't as engaging as Mirinae's later games and doesn't quite fit the game. It's more in line with what one would expect from a cutesy platforming game.
The player takes on 9 missions as Captain Lee, in hunt for the android terrorist organization Metalabor, who stole the new element Mega Plutonium K to threaten world peace. And they would have gotten away with it if they weren't so foolish as to kidnap Captain Lee's sister, to blackmail their father - a famous scientist - not to reveal the weakness of the fabulous energy source. At least that is the gist of the story, who is presented in an English so bad it's hard sometimes to figure out what's going on.
The controls are top-notch, though, as is the level design. Every mission is introduced by a briefing sequence, introducing the boss of the stage and a hint to its weakness. The stages are rather long, but not as mindnumbingly as in later episodes in the series. A few of the weapon systems are less useful than others, but other than that, the game is well balanced, and powerups are in plentiful supply. Captain Lee gets a new ship for every stage, but the differences are almost exclusively cosmetical, only the vertical range of the smart bombs gets smaller with subsequent "upgrades".
The Day II is as hard as a good shmup should be, but there's at least three difficulty levels to chose from. These are mostly represented through differing scrolling speed and weaker bosses, but for some reason the program doesn't offer a menu to select them, but the difficulty is rather determined by which of the three disks the game is booted from. In consequence, the hard and easy levels also skip the intro cutscene.
The game also first introduces Samtong, Mirinae's early, yellow mascot. It would haunt many following games with copyright warnings and cameos, and even got it's own game to star in later - that was developed by Sailon Soft after the split, though.