Tension is, per its own description, a "queer cat and mouse romp for two." 'Romp' is getting maybe a non-standard usage here, as the game tends to involve really rather a lot of murder and the themes that it treats with can get quite dark.
The PDF is 24 pages, with a very clean, readable layout and a few small graphics. It didn't feel like it was hurt by its lack of illustrations, but they might have helped to anchor the game's mood and tone even more.
Speaking of which, Tension takes Hannibal and Killing Eve as reference points, so its mood and tone are complex. It's a macabre romance, or a gothic tragedy, or an upbeat slasher flick, depending on how you look at it.
Structurally, Tension is tight. Every scene drives the two main characters together, and every scene forces them to think about what they're doing and why they can't stop. The game opens with a chance encounter, and it closes with a point of no return, and this format launches the players like a projectile towards the end.
The PCs aren't alone in the setting either. Both characters also have orbits--members of the supporting cast that are connected to them. Orbits have built-in connections to the main characters and come with compelling hooks, but their main purpose is to die.
Mechanics-wise, Tension uses a deck of Tarot cards to shape each scene. Both players have a hand of five cards, and can play them for various effects. Minor arcana are mood beats. Major arcana introduce orbits. Anyone can discard a card to kill an orbit, even if they're not in the scene, and both players have a list of things they can uniquely do by discarding a card.
The players' unique actions are extremely interesting and in-genre, and can be anything from ret-conning the scene into a dream sequence (although mechanically this doesn't un-kill orbits) to solving problems that have been introduced into the narrative. Uncomplicating the characters' lives is as easy as playing a card, but the characters don't *want* their lives to be uncomplicated. Their messy attraction keeps driving them together.
Because of the way gameplay flows in Tension, "scene" doesn't quite feel like the right word to encapsulate ten cards' worth of action. Confined to one place at one time, ten cards might make for a very cluttered environment. "Episode" fits better, and each session of nine scenes feels like it's basically a season of a show.
For player tools, Tension includes a quick reference, a rundown of safety mechanics, and really clear, direct writing to make it easy to pick up.
Overall, Tension is a cool game made well. It's very not for me (I legitimately struggle to comprehend the level of hotness it would take to let serial-killing fly in a relationship), but if you *do* like the material it's based on, I think you'll have a really good time with it.
Theoretically, Tension is also reworkable with a few tweaks, so if the serial killer bit is a deal-breaker, you could have the killer be a rebel or a monster or something else that's innately transgressive instead.