Let's start with the good aspects:
Beautiful game. Kinda like a The Legend of Zelda/Dark Souls mix with awesome pixel graphics. I love those games where you have to look in every corner and always keep an eye out for secrets and hidden passages and Hyper Light Drifter does a great job here. Often you have to keep a certain area in mind to come back later when you collected enough keys, crystals or changed something so that the path is cleared. I think I spent about 7 hours in the northern area alone and still haven't cleared it 100 %.
Also the game manages to create a great atmosphere without anyone ever saying anything. The whole game is about pictures and sound but that principle works like a charm. When people "talk" to you, they show you pictures of what has happened. Add the calm yet not too calm background sound and the beautiful background views at the edge of a cliff and you get a game that really drags you into it.
The combat system is definitely worth mentioning: Simple button-mashing won't get you anywhere. You have to time your attacks to use certain combos or attacks all while trying not to dash off the edge of a small platform that might disappear any second. Thus the combats can get frustrating from time to time, not in a way that makes you throw away your keyboard but rather makes you think "Dang it! I got this! Next try!". (I think myself a pretty frustration-tolerant person btw, so maybe that's a downside for the impatient :D)

Now for the "bad":
Well, for one there is no online-coop... I started playing local with a friend and we wanted to continue when we were both back home, but nope, that's not how it works... Also there's no cloud saving, so when you start at your laptop (like I did) and then switch to you computer or even log in at a friends computer you won't find your savegame. Easy drag-and-drop savegame transfer doesn't work either, you have to change some lines in the savegames code for that to work.
Then there're some minor things that bothered me during coop, but I guess that's mostly personal taste or things you just need to be aware of while playing: Whenever player 2 enters the game, you loose 1 health point and freeze for a moment. Player 2 cannot find/activate hidden passages and switches. Also we noticed that when you play with 2 screens connected you can move the mouse out of the game without noticing and when you click the game minimizes. When you open it up again, player 2 is gone and you need to pay 1 more healthpoint to bring them back.
And why the Dark Souls comparison? Well, there were some fights that were just overwhelmingly hard, especially when you're playing coop. We (kind of accidentially) started on "easy" in our first run and the northern boss had 3 health bars we needed to get down. (Btw if you're up for achievements pay attention on the difficulty you start with. Some stuff cannot be unlocked depending on the difficulty) When I started a solo run on "standard" (the highest you can choose when you didn't complete the game yet), it only had 1 bar and I cleared it easily. So apparently the mobs are scaled up when you're in coop which is good to start with, but somehow this scaling seemed a little over the top... (Or maybe we were just stupid noobs at the time)

All in all definitely recommended!

Let's start with the good aspects: Beautiful game. Kinda like a The Legend of Zelda/Dark Souls mix with awesome pixel graphics. I love those games where you have to look in every corner and always keep an eye out for secrets and hidden passages and Hyper Light Drifter does a great job here. Often you have to keep a certain area in mind to come back later when you collected enough keys, crystals or changed something so that the path is cleared. I think I spent about 7 hours in the northern area alone and still haven't cleared it 100 %. Also the game manages to create a great atmosphere without anyone ever saying anything. The whole game is about pictures and sound but that principle works like a charm. When people "talk" to you, they show you pictures of what has happened. Add the calm yet not too calm background sound and the beautiful background views at the edge of a cliff and you get a game that really drags you into it. The combat system is definitely worth mentioning: Simple button-mashing won't get you anywhere. You have to time your attacks to use certain combos or attacks all while trying not to dash off the edge of a small platform that might disappear any second. Thus the combats can get frustrating from time to time, not in a way that makes you throw away your keyboard but rather makes you think "Dang it! I got this! Next try!". (I think myself a pretty frustration-tolerant person btw, so maybe that's a downside for the impatient :D) Now for the "bad": Well, for one there is no online-coop... I started playing local with a friend and we wanted to continue when we were both back home, but nope, that's not how it works... Also there's no cloud saving, so when you start at your laptop (like I did) and then switch to you computer or even log in at a friends computer you won't find your savegame. Easy drag-and-drop savegame transfer doesn't work either, you have to change some lines in the savegames code for that to work. Then there're some minor things that bothered me during coop, but I guess that's mostly personal taste or things you just need to be aware of while playing: Whenever player 2 enters the game, you loose 1 health point and freeze for a moment. Player 2 cannot find/activate hidden passages and switches. Also we noticed that when you play with 2 screens connected you can move the mouse out of the game without noticing and when you click the game minimizes. When you open it up again, player 2 is gone and you need to pay 1 more healthpoint to bring them back. And why the Dark Souls comparison? Well, there were some fights that were just overwhelmingly hard, especially when you're playing coop. We (kind of accidentially) started on "easy" in our first run and the northern boss had 3 health bars we needed to get down. (Btw if you're up for achievements pay attention on the difficulty you start with. Some stuff cannot be unlocked depending on the difficulty) When I started a solo run on "standard" (the highest you can choose when you didn't complete the game yet), it only had 1 bar and I cleared it easily. So apparently the mobs are scaled up when you're in coop which is good to start with, but somehow this scaling seemed a little over the top... (Or maybe we were just stupid noobs at the time) All in all definitely recommended!