[Please note that this review is my own from GOG but expanded and edited to fit the review standards of Glitchwave. I hope this won't get me perma-banned on my first day.]
If you like third-person or top-down stealth games (
Hitman,
The Elder Scrolls V: Skyrim,
Heat Signature) buy this game. I've put 90 hours in and have completed probably 80+% of the side-quests, including the DLC, as well as completing the main quest line and had a blast.
However, there are many annoyances that detract from the user experience. With a bit of experimenting, though, the game really opens up and becomes very fun.
You MUST save-scum. The one-shot-kill environmental features and unrestricted (few to no invisible walls) fall damage means you will have to use the save system intentionally. Since even side-quests can have different endings, you are encouraged to play out the various options by quickloading and trying a different approach.
Many things aren't adequately explained to you such as the icons in the menus, how or why to upgrade weapons and armour, the stash system (available at the safehouse and every fast travel point and crafting bench) and how to upgrade your "magic" abilities, how to use magic properly, differences in weapons, necessity of dodging or techniques for combat (the latter two aspects encourage experimentation).
You cannot ghost through the game which may put some people off when the game says you can "choose your playstyle". Combat is required for three fights during the main-questline and one during the DLC, so watching for better weapons and crafting upgrades for them is also necessary.
While the camera is a bit finicky at first, it doesn't take long to get the hang of it. What is inexcusable, though is that enemies and environment features one floor above you sometimes don't load in or are invisible until it's too late to do anything about them.
As mentioned above, time does need to be invested to figure out the systems. Test out different combinations of weapons, find the balance between armour stats, aesthetics and movement speed, use the sense mode liberally and the more you use magic, the more fun you'll have.
If you can get over the lack of guidance from the devs, this is a gem of a game.