All about the money:
This might be a misleading subtitle, as we have no intent to bring this game to market. But as an exercise we thought about what engine we should pick if we were to sell Couch Divers™.

Unity engine is free to use if the revenue is less then 100.000 dollars yearly, when surpassing this a monthly fee of 75dollars is charged or a one time payment of 1.500dollars.
Unreal engine is free to use if the revenue is less then 3.000 dollars per quarter, when surpassed a 5% of the revenue will be charged. 

So in theory (not counting extra costs for marketing, greenlights, etc… and just purely looking at revenue) if we were to charge 15dollar for each copy of the game, we would find the following conclusions:

The chance is low that we’d sell more than 800 copies(=12.000dollars revenue, limit for Unreal),  but the chance is even less than selling 7000copies(=105.000dollars revenue, limit for Unity). So picking Unity or Unreal are both safe bets. But if our game became very popular for some reason(obviously because our game is the best) and we were to sell more than 7000 copies, we’d have to pay a fee of 1500dollars when using Unity BUT a 5.250dollars fee when using Unreal (5% of the revenue). When selling 2000 copies (at 15dollars each, giving 30.000dollars revenue) our fee for Unity (1.500dollars)and Unreal(5% of 30.000 = 1.500) would be the same. Anything more than 2000copies, and using Unity would be cheaper.
The conclusion is, that for our game, Unity has no advantage over Unreal based on profit. Unless of course our game blows up and we sell more then 2000copies, in which case Unity would be cheaper.

Versatility of platforms:
Unity gives access to a bigger range of platforms than Unreal. Unity gives access to: iOS, Windows Phone 8, Tizen, WebGL, Android TV and Samsung SMART TV, Xbox One & 360, Windows PC, Android, Mac OS X, Playstation Vita, Linux, Web Player, VR(including Hololens), SteamOS, PS4, Novint Falcon, Wii U, Kinenect, ...

Unreal gives access to a smaller range of platforms: iOS, Android, VR, Linux, Windows PC, Mac OS X, SteamOS, HTML5, Xbox One, PS4. 

Our art style:
Unreal Engine is, for now, superior to Unity when it comes to graphics, however we want to go for a more cartoony-vibe for our game. To do this we don’t really need the power of Unreal Engine.

Our programming test:
Just to be sure of our choice, we tried to see how far we could get, programming in unreal. As you can see in the Unreal Build we didn’t get really far. We lost a lot of time looking things up. First we had to figure out how to create a new GameMode. We also had to set up visual studio for compiling with Unreal Engine.

After these steps we could finally start to implement our ideas. Almost immediately we ran into some troubles when we tried to spawn boxes at random positions and with an upwards velocity.
By this time we had already lost a lot of time, especially as we achieved so little in this time.

Given the same amount of time when programming with Unity, we achieved a lot more (moving boxes, moving player).

An extra note: Robin and Nick have programmed in C++ more times than in C#. Seeing as this game is also a training exercise, they want to program in C# to learn that language better. Unity scripting is in C#, so Unity might be the best choice with the aim to learn the language of C# better.

So we stuck to our initial choice of Unity.