This is an unreleased and unfinished game that came to light relatively recently. Though it's clearly unfinished, this mostly manifests as what we can generously call "presentational eccentricities" that would have presumably have been ironed out before release. Things like the very default-looking font used for a lot of the text, and things like getting a "bonus for breaking stuff" at the end of each stage. It is totally playable, though, and it's a shame that it never got officially released, because it's a lot better than most western-developed arcade games ofthe nineties.
The main thing that stands out in Danger Express is its aesthetic, which I've seen other people describe as looking like a fake videogame you'd see characters playing on a TV show. That's a fair enough description, but while I played, what came to mind for me is that it was like some long-forgotten vanity project of a straight-to-VHS no-budget action movie had somehow got a licensed tie-in videogame. All it really needs is the addition of a cutscene starring Cameron Mitchell and it'd be perfect.
What is that aesthetic? It's an amazing combination of sprite scaling and digitisation, with real life actors dressed as generic goons walking in and out of the screen. There's even some kind of psuedo-live action cutscenes! They're not really proper videos, but more like short gif-like animations using frames from a live action video. To maximize the amount of scaling that gets done, Danger Express also eschews the usual horizontal scrolling seen in most beat em ups in favour of having all the stages go into the screen like a melee-based Space Harrier. It seems unlikely, but I wonder if the developers had played the PC Engine game Jinmu Densho, which is a similar concept, mechanically at least (though to be honest, Danger Express is a much better implementation of the concept).
Naturally, then, a train is the perfect setting for such a game: lots of narrow corridors, giving a good reason as to why you're walking in a straight line through waves of enemies. So that's how it goes (except for a few outdoor excursions to backalleys, docks, or at the casino): you walk from the back of the train carraige to the front, killing everyone who tries to stop you, including soldiers, ninja, strippers, wrestlers, bikers and so on. Interestingly, some stages give you a rifle, while others are purely melee, except for the occasional inclusion of a temporary pair of nunchaku that shoot balls of lightning.
The most surprising thing about Danger Express is how good it is, though. Most games that use digitised sprites tend to be awkward, stiff and no fun to play, while western arcade developers in the nineties had a penchant for putting out cynical, hateful coin eaters. Danger Express bucks both trends! While the action isn't exactly super-smooth, it's fast and enjoyable enough to cover up the cracks, and the difficulty is actually prety reasonable: on my first attempt, I got about four stages into it (out of nine), and I think it's probable that with some practice, it could actually be 1CCed by a skilled player.
