When comparing Genome2D vs BYOND, the Slant community recommends BYOND for most people. In the question“What are the best 2D game engines?” BYOND is ranked 29th while Genome2D is ranked 47th. The most important reason people chose BYOND is:
BYOND is in active development and updates are released constantly.
Specs
Ranked in these QuestionsQuestion Ranking
Pros

Pro Lightning fast
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
Pro Cross-platform mobile, desktop and web
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 :)
Pro Haxe!
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.)
Pro Access to direct draw features
Has access to direct draw features so you can make you own rendering structures (scene graphs etc).
Pro Automatic dynamic batching
Automatically batch geometries with dynamic batching techniques (by using constant buffers).
Pro Component based architecture
Pro In active development
BYOND is in active development and updates are released constantly.
Pro Easy to use
The software itself is very easy to learn and use for beginners.
Pro Helpful community
BYOND's community is relatively large and extremely helpful. Any question a beginner or an experienced user may have is quickly answered.
Pro Large Community
Fairly large player base and multiple games to play.
Cons
Con Lacks documentation
The API documentation is minimal, there's not many tutorials and the ones that are there are very small and only cover the basics. If you want to learn how to properly use it, you have to ask the community or read the source code and figure it out.
Con Not too many games to showcase it
Con Slow development rate
Con Highly supports multiplayer, but can make solo games ready for download.
Con Exclusive programming language
The language is known as DM, and is modified using Dream Maker. It is an object oriented, interpreted language, which closely resembles C++, Java and PHP. More information available in the DM Guide.
