When comparing Corona SDK vs Urho3D, the Slant community recommends Corona SDK for most people. In the question“What are the best 2D game engines?” Corona SDK is ranked 27th while Urho3D is ranked 43rd.
Ranked in these QuestionsQuestion Ranking
Pro Very simple to use
Corona SDK is completely free as of March 2, 2015. That includes pro-tier plugins.
Pro Lua syntax
Uses the great and easy-to-learn Lua programming language.
Pro Amazing learning curve
Corona does not throw photoshop-like madness full of buttons editor. You can go as fast as you want, learning and building game from ground up. Eventually, you'll learn how much corona is doing for you. But to start you don't have to master complex editor software. It's a great tool to learn to start game development if you want to learn how to program and make games. Your experience will be 100% transferable to any other Pro game engine.
Pro Corona Simulator
Corona SDK ships with Corona Simulator, which runs your game/app directly on your PC/Mac and updates every time you make changes.
It provides immediate feedback to your actions, you can see your changes right on the screen, without necessity to make build to device. Getting instant feedback really boosts tenfold prototyping and development speed.
Pro Good documentation and lots of tutorials
Pro Cross-platform desktop and mobile
Corona works on OS X, Windows and Android (including Kindle Fire & Nook).
Pro Great community
Pro Ability to call any native (C/C++/Obj-C/Java) library
Pro Very comprehensive API
It's very quick to get things up and running with Corona SDK. The API is extensive and while it's not 100% feature-complete with the iOS API, it's close enough that you could create tons of games and never run into a roadblock.
The API docs can be found here.
Pro Content scaling
It's easy to create a game that looks good on many different sized mobile devices.
Pro Live builds - update builds running on a device automatically
With the live build feature, once you have created a build and installed on a device, you get lightning fast turnaround times because any change on the code or data is updated to the devices running the game (within the local WiFi) immediately. So changes can be tested on the real hardware within a very few seconds.
What's even more impressive, this even works flawless with multiple devices running the game. You have to use it to learn how good of a feature this is while development and even more, while doing QA. Imagine fixing bugs and everyone of your QA team/friends/whoever helps to get your game done, has all changes on his device without doing anything but waiting 5 seconds - outstanding.
Pro Well supported
Pro Includes a lot of samples
There are a lot of sample projects included with the engine for both C++ and Angelscript. They are mostly very simple applications built to demonstrate the engines capabilities and features.
Pro Free and fully open source
The entire engine is open source and makes use of other open source libraries. Source code is licensed under MIT and available on GitHub.
Pro Very high code quality
Urho3D is written in a modular and super-clean way, so that it can be integrated into the other parts of your game seamlessly.
Pro In constant active development.
Bugs are usually fixed that same day. Core devs are very active on forums. New features are always being worked on. HTML5, DirectX11, and OpenGL3.1 support have recently been added. (as of 4/15/15)
Pro Good documentation
The documentation for Urho3D can be split in two parts: auto-generated from class references and documentation written to cover the various aspects, features and systems of the engine. The written documentation is pretty good. It covers most of the aspects of the engine in clear and understandable English.
Pro Fat-free codebase
Only use what you need.
Pro Good 3D level editor
Pro Small turnaround times while developing
Builds are quite fast, aids in rapid development.
Pro Unofficial Oculus Rift support
Information on enabling OR support can be found here.
Pro Does not require an editor to get going
Con Making a device build requires internet connection
To build your app for the device (iOS/Android/AppleTV) Corona requires to fetch resources from online. This would include base application template and plugins. This allows not to perform local build or use Xcode or Android Studio to do a build. Even Large games/apps would build very fast with good internet connection.
Your code never leaves computed. Corona SDK would transfer some information to determine which plugins and pieces has to be transferred in order to make a final steps in build.
As a bonus - you get basically one button press to get from your Corona Simulator game to game on a device.
Con Closed source
Since you don't have access to the code, you can't make changes to the SDK. You even have to implement workarounds on issues that have long been reported, but never fixed.
Con Free, but not completely
Such conventional plugins as a reference to AdMob for example, cost $300 per year!
Con The UI can be hard on the eyes
Urho3D's UI lacks polish and and could cause eye strain.
Con May be a bit hard to get started
To install Urho3D you need to get the archive from GitHub (be careful to download the master branch) and extract it. After that, you need to compile the engine with CMake. If all the dependencies are installed, then it should be a straightforward process, otherwise you will need to track down and install all the missing dependencies.
For people who don't have much experience with CMake this whole process may seem a bit like magic. For people who do have experience with CMake, the whole installation will be relatively easy.