Unreal Engine 4 has a visual coding system called Blueprints. Think of them like the event system in RM except you can also access all the C++ functions they call directly, and create new ones as well.
Here's a short video where some dev at Epic makes a simple 2D game using UE4 and Blueprints only -- not a single line of code:
https://www.unrealengine.com/blog/shipping-tappy-chicken
Graphics for UE4 and Unity, like any 3D engine, are a lot more expensive usually, and it's harder to get into than 2d illustrations or pixel art. That is the big drawback of 3D engines. The upfront complexity and learning curve is also vastly different. But personally, after The Vendor, I'm going to collaborate with a few friends on a UE4 game. For me UE4 is just the absolute best alternative for 3D engines now because of one huge element: the source code is open sourced, and you are allowed to do whatever you want with it. That is absolutely huge. It means I -- and anyone else -- can modify the editor and engine however we want, to make it do exactly what we want, without having to wait for Epic to do it for us. The pricing model -- 5% of gross profits -- might sound like a bad deal if you plan to earn a lot, but with the engine on offer and the open source nature of it, it's a steal.