I'll start with what I like here.
+ Your graphics are quite nice to look at, reminds me of the original Zelda games.
+ Nice work on the minimalistick UI, it doesn'y get in the way.
+ The control scheme is very simple to grasp, no complication there.
+ The explorable areas are a nice touch when they work (more on that later).

Now for what isn't working.
The issues here are small but they can break the experience, quite a bit.
The player's collision box keeps me from moving through some spaces (doorways mainly),
I actually thought I couldn't go through the first locked door (even though I had a key), but the problem was I couldn't quite fit through the doorway and thought at first that I maybe had the wrong key or that the first door wasn't unlockable yet, so I ended up trying to explore the wide open space south of where you start (got killed instantly but I'll get to that later)
I tried the first door later and actually got through, which didn't take long for me.
Sidenote: Corners on things like pillars are easy to get stuck on because you kinda just stop moving when you're trying to get around a pillar, another collider issue it seems.
Another collision box issue is the enemies.
The hit boxes for your enemies are too big, they barely even have to get close to you to kill you, which feels unfair, because you don't know which distance to kill from.
If exploration is what you were going for you kinda killed it in the first room,
I died as soon as I went to the open space south of where you start and didn't even see who or what was there, or what killed me until later. The feeling I got was that those open spaces were dangerous. Exploration is what you were going for, but you accidentally punished it in the very first level.
When I got through the first unlockable door, I hesitated to go into the explorable room, because I thought I would get insta - killed again. I tried anyway (because I needed another key) and managed to kill the snake that was in there (and got the other key).
That's when I saw the other explorable space I got insta - killed in. I realised that I only got killed because the snake (which already had a big collider on it) was too close to the entrance. Maybe this was a mistake on your part, or it was intentional, I'm not sure.

Final thoughts
I didn't really have any issues with the rest of the rooms after that, (except the explorable area with the three snakes I couldn't kill).
The only thing I noticed, (which is really just a nit - pick on my part since you're still in development, so its probably irrelevant) was the portal you walk through that ends the game.
It feels awkward and out of place, not as much because of the story cliff hanger you added, but because the room doesn't require any exploration to complete the game. You could end the level right there and miss the goodies you could've found in the other explorable areas.
It kinda feels like a missed opportunity for me as a player, because I ended the game without finding what's in those hidden areas.
But I guess that's just me.
Hope that helps!

Darkour
I'll start here with what I like
+ The music is pretty good.
+ The art style is minimalistic in a not lazy way, reminds me of Vector.
+ The movement and jumping controls are smooth, no bugs there at all.
+ The shifting through worlds concept is pretty neat, reminds me of Guacamelee. It holds alot of great potential as a game mechanic.
+ Openning menu is very inviting.
+ Overall the game runs very smooth, no complaints there.
However,
- The design of your levels needs work especially because they are early levels.
- The game is way too hard way too soon, I couldn't get past level four (struggled through level 3)!
The reason the game is hard is because of the shifting through worlds mechanic and its button placement.
I have to remember too many controls at the same time which is too much.
I'm playing on a mouse and keyboard so maybe its easier with a controller.
I would suggest using simpler and easier levels at the start to get the player used to things, then maybe use 3 and 4 as expert challenges or something like that.
Minor issues so far are;
- No exclusive fullscreen so the game opens to a large window in the corner (I've had this problem in my own games, you can google it).
- No pause menu, so I couldn't quit the game unless I clicked X in the top right corner.
Hope that helps, feel free to check out my game.

Sorry but I can't actually get into the game. Pressing enter won't work when I try to select new game.
I get credits when I hit shift, and the disclaimers and stuff but thats all.

Thank you so much for the reply, I've been having something of a feedback drought lately XD.

I've taken note of everything you've said and I'll get to work on it

You're not the only one who complained about telegraphs, or spells, I'd better figure those out coz I understand how important it is to telegraph enemy attacks and support my own gameplay features.

Thanks again, and good luck to you!

P.S Sorry I couldn't try your game with my xbox controller (usb cable died on me).

Thanks for the reply and the feedback, really means alot to me.

I was actually adding controller support to the game when my USB cable died on me (last month I think it was), sorry I couldn't add that for you.

Enemy strength does need tuning for sure, I think as the developer I've become insensitive to certain difficulty because I'm always testing, you're not the only one who complained there.

I should have put it in there that spells only work with guns (not the saw blade or the bazooka), my apologies there.
Spells overall do need work.

I'm glad you liked it. `I'm definitely taking your feedback on board. Thanks again.

Tried your game out just now.

Here are some of my thoughts;
+I really wish there was a tutorial, last time I was this lost I think it was Terraria.
+It seems like the hatchet is very important to alot of what you do in the game, I would suggest giving one by default.
+ The claiming of territory, how does that work?
+ Your help page doesn't seem to have a scroll bar so I couldn't read the instructions (I'm using Fire Fox so maybe its my browser.
+ Maybe its my connection because the game lags on my end.
+ The low poly look is a wise choice for a browser game, it should keep latency low (I'm implementing similar visuals in my game).
+ The crafting of a fruit spear was easy enough but the tool feels useless, I tried to kill a chicken with it.
+ The game feels like a pototype because the only animals I encountered were chickens.
+ I don't quite understand all the percentages you placed on the left hand side of the screen (I get health but the sleep and meat percentage don't seem to mean much).
+ The server froze me out for some reason so I can't get back in.

Over all
I understand your concept from just looking at it but the game still feels like a prototype you're trying out.
Its a bit hard to actually get into and I wish that there was a little place I could run around and learn the basics quickly.
I wanted to build my own walls and claim land but I don't even know where to start, I can barely craft a work bench let alone build walls.
I wish the visuals conveyed more of whatyou were going for aswell, right now they're a bit too simple, try this Youtube video to see what I mean https://www.youtube.com/watch?v=H1oNuKChsdU

But you can take all this with a pinch of salt, I don't usually play survival games, so I can't say I know much.
Keep going at it and good luck to you.

Here's my game feel free to try it out.
https://roastmygame.com/game/project-gunsbritannica

Thank you for your response man, much appreciated, I actually thought no one else was going to even look at this again.

I just tried your game out (love the menu by the way).
Your swinging mechanic is hard to get the hang of.
I think the platforms might be too low or maybe it needs a simpler level. But the flow is not quite there.
I think it might also be the fact that swinging with the two mouse buttons aswell as arrow keys and the space bar is too much input to have to use.
If you've ever played the Amazing Spiderman games, I think they used holding and releasing to implement swinging.
If you could hold and release one button it might be easier.
Aiming to get your rope to a ledge is also pretty taxing mid swing because gravity doesn't help much (nothing wrong with it, it functions but design wise it doesn't work, its too easy to click the wrong button).
Other wise all your mechanics work functionally, no bugs on my end (Windows build) and your level background looks nice, again well done on the menu.

Here you go, hope this helps (originally a reply to your roast of my game).
I just tried your game out (love the menu by the way).
Your swinging mechanic is hard to get the hang of.
I think the platforms might be too low or maybe it needs a simpler level. But the flow is not quite there.
I think it might also be the fact that swinging with the two mouse buttons aswell as arrow keys and the space bar is too much input to have to use.
If you've ever played the Amazing Spiderman games, I think they used holding and releasing to implement swinging.
If you could hold and release one button it might be easier.
Aiming to get your rope to a ledge is also pretty taxing mid swing because gravity doesn't help much (nothing wrong with it, it functions but design wise it doesn't work, its too easy to click the wrong button).
Other wise all your mechanics work functionally, no bugs on my end (Windows build) and your level background looks nice, again well done on the menu.