Jotun is a 2D miniature Shadow of the Colossus. If that appeals to you, get it.
You play as Thora, a viking warrior woman who has died at sea. Because her death was not honorable (that is, in battle), in order to earn her place in Valhalla she must prove herself to the gods by defeating the giants known as the Jotun.
The game takes place over five worlds, each of which has two exploratory areas and a boss fight (except for the first world, which only has one exploratory area). Each exploratory area has a rune that must be obtained before the boss can be fought, along with optional collectibles that either power up Thora (by giving her extra health or a god power) or give a bit of background on Norse mythology. Each area has its own aesthetic and background in mythology, along with some hazard or gimmick that usually returns in the boss battle.
Jotun features beautiful, hand-drawn graphics that are a joy to look at. You never know what you're going to get when you enter a new area, or even when you turn a corner. In certain points, the camera will pan out so you can see the stunning background or surrounding area. However, while the game is beautiful, it also feels a bit... synthetic. The environments look fantastic, but you can seldom interact with them. (Of course, it's very possible that the only reason I'm commenting on this is because I'm in the midst of Breath of the Wild, where the basic rule is if you can see it you can go to it.) Exploring the various worlds, finding new obstacles, and discovering the collectibles is certainly fun, although sometimes the areas felt a bit too big, and I wanted to just get to the spot I was trying to reach.
While gathering the collectibles is fun, the highlight of Jotun is definitely the boss battles. The bosses follow the basic theme of their world, and also feature the hazards of the exploratory areas, but usually with an additional twist. For the most part, they are challenging, but fair. Because you know generally what the hazards are, you can focus on foreseeing and dodging the attacks from the start rather than trying to figure out what they are going to be. (The exception to this is the final boss, which I felt was a bit too hard. It mostly consists of the boss throwing massive homing missiles at you, which require near-perfect rolls to dodge, and dashing halfway across the map by the time you reach him.)
The controls are simple and responsive. You move with WASD, perform a short roll with space, and do a quick weak attack with LMB and a slow strong attack with RMB. The weak attack isn't that quick, so timing is still important. Because Thora isn't that fast and enemy attacks hurt you a lot more than your attacks hurt them, battles generally consist of dodging attacks and staying safe while looking out for openings to damage the enemies. (It felt a bit like a 2D Monster Hunter fight to me.) In addition, you can collect god powers to aid you. You scroll through god powers with Q and E, and activate them with F. Once you've collected a couple of the god powers, accurately scrolling through them in the heat of battle can be a bit tough, but besides that they are definitely helpful.
Jotun draws heavily upon Norse mythology, which helps it create an interesting, vibrant world. We travel through a variety of locales, and encounter various mythological figures and creatures. In addition, after each boss battle, we learn a bit more about Thora and her past. All voiced dialogue in the game is in Norse, which helps cement the aesthetic.
The music was atmospheric and appropriate, and... that's about all I have to say about it. If you can't tell by now, I don't usually have much to say about a soundtrack unless it really grabbed me, and this just wasn't the type of soundtrack that grabbed me. It felt to me like the music would change subtly depending on which part of the area you were in (although that could have just been my ears playing tricks on me), which I thought really helped shape the music to the appropriate mood.
Despite a couple of complaints (some areas are too big, world isn't very interactive, some parts of the boss battles feel unfair), Jotun is a solid, short (5-6 hours) action-adventure game that you should definitely pick up if you enjoy battles against epic, tough-but-fair bosses.