Hello All
I'm currently working on a 2D Pixel art art game that at the end of the day will be similar in workload to Stardew Valley.
I'm wondering if Unity would have all the requirements for making a game like that, or if another engine would be recommended. 
I'm currently using Unity so I just find myself wondering if I'll hit a wall at some point in capability, so I figured I'd ask some of you guys with way more experience, as I have barely any experience with the engine.
 

I've also heard Unity adds a lot of 3D stuff that weighs down the program, Is that true?

Thanks for taking the time and God bless

A game like Stardew Valley would be quite do-able in Unity.  As for performance, you just need a semi-competent programmer and you should be fine.  Unity has been used to make hundreds of 2D and 3D games, much like the Unreal Engine.  Honestly take your pick, either will do fine.  As for others, I'm sure there are a lot of other engines, but what is your or your programmers language of choice?  Unity uses C# and Unreal uses C/C++ and Blue Prints.

On the programming side I'm fine.

Both me and my friend that are making the game have been using C# for a bit now so we're pretty good when it comes to programming.
I've heard Gamemaker is good for 2D...

You just have to look at Unity showcase to see whats possible here. 

Its just up to the capabilities of you and anyone who works with you. Depending on your skill set other game engines might be better suited but Unity is in no way incapable of producing the type of game you are making.

Thanks
The problem I had with using the Unity Showcase is that it butters everything up.
I've heard of several regular problems Unity has with 2D Rendering, that you would never find on their website, but you can find it everywhere else.
Two big ones being the 3D one and that tiles don't render right, which I'm currently using a hack to "fix"

Inquire on their forums or post questions here about your "issues".  I doubt Unity has problems rendering 2D tiles.  I also doubt you need a hack to "fix" it.  I suspect it's a lack of experience more than anything.  Games like Pillars of Eternity and Wasteland 2 were made using Unity.  Wasteland uses 2D tiles for the ground and it's a AAA game.  I would stop listening to rumors to be honest.  They're typically started by inexperienced people or trolls.  If there are actual problem, people will post evidence and the Unity or even Epic's teams are fairly quick to jump on any real bugs.

Unity is 100% capable of making a Stardew Valley clone.  Just like Unreal Engine is.  Game Maker is rather amateur-ish at this point though could likely also do a Stardew Valley clone as it's not a very taxing game (could likely easily run on older mobile platforms to be honest) since it was used to make Crashlands which works on mobile too.  But I'm not sure if it's free either.  Again, you asked for advise, we gave it.  It's for you to ignore or accept.

If you have technical issues with using any of the mentioned engines, make a new post.

I guess I did get a little off topic there ? 
Thanks for answering my question!