Firstly, Unreal Engine 4 is now free, while Unity is $75 a month. And, because of that, you should switch over, if for nothing else than cost saving.
Secondly, Unity seems to be designed around a brightly colored, cell-shaded, look, while the Unreal Engine goes for flat our realism. So, for a game like this, I would recommend using UE4. Plus, if you use UE4 your developer street-cred would go up by leaps and bounds.
Last I heard they were going to UE4 and not Unity…
Well, let me counter that with a few points. UE4 is harder and slower to develop for, has less of a development community, less premade available stuff and does take a 5% revenue share from your sales.
Also the brightly coloured cell shaded look isn’t intrinsic to Unity, and it can be made to look quite realistic - youtu.be/iV-224nMwN8
Having said that, we’re most likely going to use UE4, and I love it to bits 
Wait what? You are going to use UE4? Not Unity? What? I feel like this should be a headline somewhere… Really now?
Most likely UE4 yeah, Unity doesn’t quite do everything we need, and is harder to make pretty too.
But that’s a while off anyway.
What game engine is it currently running ?
It’s running on Kee, their inhouse engine
i always thought that unity is made to be simple for simple looking stuff… like pay-to-win games all over the web 
but yes, have to say +1 for UE
[quote=“xABSOLUTIONx”]i always thought that unity is made to be simple for simple looking stuff… like pay-to-win games all over the web
but yes, have to say +1 for UE[/quote]
Never play KSP eh? But KSP is also REALLY pushing Unity past what it was designed for, there are some things that “work” that shouldnt work with Unity and only because they had the Unity devs help them get it working. That said though I think UE4 will be better, Unity is great for starting out but it IS rather limited in certain aspects, for KSP it REALLY needs a better way to model physics and such, Unity can only do so much there since it is a single thread.
Too be honest, Unity is the easier one to use and code in my opinion. I do not know how well Jayelinda and Caswal are with programming in C++ or XCode or what else UE4 might accept, but Unity uses C# and Javascript (in a sort Unity variation from it). Unity allows for quick and easy making of things, but as Daffy said, it costs quite some time and effort to make pretty (read: to make it look quite realistic) Unity is just perfect for things like KSP and Borderlands(Borderlands isn’t made with Unity! I know! Just an example), which don’t need to be super realistic in it’s renderings.
And now Unity releases their Unity 5 engine: youtube.com/watch?v=pd7JN_idUnQ
Looks pretty damn amazing to me, too. And a lot gets easier. So it might end up being a hard choice after all.
Not so hard, unless they start giving affordable full source code with Unity 5
what exactly are you after that requires you to need the full source code?
Getting a lot of the stamping/deforming-y stuff working properly for one thing
[quote=“WizzyThaMan”]And now Unity releases their Unity 5 engine: youtube.com/watch?v=pd7JN_idUnQ
Looks pretty damn amazing to me, too. And a lot gets easier. So it might end up being a hard choice after all.[/quote]
it still doesn’t beat this imho - youtube.com/watch?v=Csk9BLW0fv0
and i have to say, that Unity is amazing in doing everything while UE is meant to do amazing games in it’s core
[quote=“WizzyThaMan”]And now Unity releases their Unity 5 engine: youtube.com/watch?v=pd7JN_idUnQ
Looks pretty damn amazing to me, too. And a lot gets easier. So it might end up being a hard choice after all.[/quote]
The coolest thing I saw in that video is those sweet big screen touch displays. Do want!
On another note, it seems that switching development from an in-house engine to a 3rd party engine would be quite a daunting task.
On the other hand, I’m very happy with how the game is now, would be awesome with Unreal Engine graphics!
The plan is to be able to afford an employee to devote their time to it. Luckily the game is built in a way that it’s not TOO horrific to do 
