Genome2D vs Blacksmith 2D

It's the fastest gpu-based framework out there for flash. It's beautifully optimised. It has very low rendering latency, low level OpenGL calls that other tech simply cannot do (ie Unity) due to Stage3D, and thus can render a lot more data quicker

Supports Windows, Mac OS X, Linux, iOS, Android, Web and native Flash.

And with the HTML5 export, it also potentially supports development for the Wii U :)

Haxe is a strictly typed programming language that saves development time but still compiles high performance executables, and can build for tons of different platforms (flash, c++, html5, java, c#, etc.)

Has access to direct draw features so you can make you own rendering structures (scene graphs etc).

Automatically batch geometries with dynamic batching techniques (by using constant buffers).

Automatically detects changes and updates bitmap cache. Allows to gain even more performance on heavy scenes and runs smoothly on old devices.

All engine code is written in ES6, fully GCC typed, allowing to eliminate all dead code from your app.

Dirty flag tracks scene changes and avoids unnecessary calculations and context calls. If no changes were made to the scene since last frame, no rendering will be done. Battery efficient.

According to the tests on the Github page, the performance is better than in Phaser!

The source code is well commented and easy to understand.

Super small build size through dead code elimination. The best for playable ads and Facebook Instant Games.