Without a doubt, that would be Salamander, a Konami game released in 1986 (wikipedia). I played the game on an MSX-2 home computer and I actually tried to beat it last year (that older entry has a screenshot plus original sound!).
There are a couple of reasons why I think that game is so hard:
- The game can be played with two players simultaneously, which shows: there’s so much action going on all over the screen that it is sometimes impossible to break through stages without any help.
- The game features multi-directional scrolling in all stages.
- There’s a frequent change of view: in most stages, you ‘fly from left to right’, however, there are 2 or 3 stages that shows your ‘ship’ from a birdsview.
- ‘Yo Save Games are for losers’. There are no save games in Salamander. You’re supposed to beat the game. And you start with only 3 lives.
That said, I beat the game: However, if you plan to play it (there’s plenty of MSX emulators around nowadays), make sure you buy the right joystick. The game is all about counting.
I read that the Wikipedia article states that the MSX version contained way longer stages. Yeah: like if I didn’t know.