jMonkey3 vs Gamebryo

Java is a well-optimized just-in-time compiled language. It's faster than languages without an effective native-code compiler such as Python or Ruby, similar in speed to other just-in-time compiled languages such as C#, while slightly slower than compiled languages such as C or C++ (with some low-level and numeric benchmarks being similar to C++).

Java also has a wide variety of high-class IDEs available.

Code can be ported to mobile (iOS is in the works) and other Android supported devices with minor changes to the code (just change some implementations that vary on the platform such as inputs and user interface). It can even run on certain Raspberry Pi devices.

jMonkey is completely free, meaning it's possible to develop and release a game with no fees or royalties. Because it is open-source, jMonkey has plenty of people fixing bugs and, adding to the engine as well as creating a variety of plugins that can be used in the engine.

Unlike some engines, jMonkey doesn't force its own IDE. You can use its Netbeans-based IDE, but you can also set up a project to work in another IDE such as Eclipse. You can still use the special tools from jMonkey's IDE in such projects.

Because jMonkey is implemented in Java, the same language its apps are typically developed in, developers will have an easier time modifying the engine to their needs.

jMonkey3 handles input from computers and mobile devices. It handles networking, physics, rendering, terrain, and cinematics.

Engine is modifiable.

The user is not compelled to use any programming architecture nor standard in order to make a project working. JME allows the freedom to use what is best for a game.

Modifying shaders can be done either via a visual tool called Shader Nodes or via GLSL that allow you to make your own shaders without the engine getting in the way or having to hack around to do so.

Gamebryo has been written in C++. Because its features are as independent of each other as possible, it allows including only the features that are necessary for a game. Also because the abstract interface and its implementation are separate, custom implementations can be made as well as default implementation extended by inheritance.

Gamebryo supports Windows, XBOX360, PS3, and WII. Several hundred cormercial titles have been developed with Gamebryo, including The Elder Scrolls IV: Oblivion, Fallout 3, Catherine, RockSmith, and etc.

Gamebryo has detailed documentations. It is provided in html files and its size is about several thounsand pages. It also includes several dozens of tutorials and demos.