o2 - it's an open-source technology for easy making 2D games and applications for mobile and PC platforms using C++ and Lua with very flexible editor. The main features are performance, usability and effective development.
Here is the test project: https://github.com/zenkovich/o2-Template
Now work in progress.
Automatic assets building and converting, automatic atlases packing, easy to add to project, flixible configuration.
Component-objects based scene graph, nested prototypes and good integration with editor
Fast and flexible UI system, a lot of default widgets, styles, integration with scenes
Easy to learn rendering system with meshes, fonts, sprites, culling, shaders and render targets.
Playing sounds, music, streaming sounds, audio mixer
Animate everything, retargeting, easy to serialize, layers, weights, IK, animation state machine, mesh skinning, editor integradion
Particle emitters with different forms, particle effects, editor integration
Rigid bodies, colliders, joints, effects
Multiplatform input processing, easy clicks and touches processing
IOS, Android, Windows, MAC OSX, Webassembly
Flexible editor "all-in-one", plugins