Gunborg: Dark Matters looks like a Metroidvania, but it isn't. Something about the layout tricked me - warrenous 2D corridors, suggesting complexity, back-tracking, several flavours of door. In fact, this is an action game - a short, punchy action-platformer game with an emphasis of repeating levels until you ace them. I think it's great.
It is a work out for the triggers. Trigger to jump. Trigger to attack. Trigger to pick up weapons. Trigger to activate a shield. Almost all of these uses require a little explanation.
Take jumping. You can double jump - then triple jump, then maybe quadruple jump! And if you hit a wall and cling to it, I think it resets. As for attacking, you have a sort of laser sword as a basic weapon, but really you want to swap it out as often as you can.
This is where picking up weapons comes in. Defeat an enemy and you might get its sniper beam, or its flame-thrower, or its heat-seeking doodads. Enemy clips are small, so you're encouraged to pick up weapons and discard them often. Luckily almost every baddy around drops something.
And if you're really out of luck, use your directional shield to send incoming fire back home. This comes into its own in some ingenious boss fights - honestly, the boss fights here are an absolute treat. But it's also a mainstay of every short, punishing level in the brief campaign.
The pleasure, of course, comes from all these things being threaded together. A short game then, but a very challenging one. And one I am already looking forward to replaying.