When comparing Rainbow vs GameMaker Studio 2, the Slant community recommends GameMaker Studio 2 for most people. In the question“What are the best 2D game engines?” GameMaker Studio 2 is ranked 51st while Rainbow is ranked 78th.
Ranked in these QuestionsQuestion Ranking
Pro Open source
Distributed under the MIT License.
Pro Written in modern C++, is scriptable in Lua
With support for Android, iOS, Linux, Mac OS X and Windows.
Pro Optional FMOD audio engine
Pro Supports Spine
Box2D integrated with Lua bindings.
Pro Quick prototyping
Pro Good user interface
Pro Well-optimized engine
Pro Has a trial version (but limited functions, can't export)
Pro Many unofficial tutorials
Most GMS1 tutorials are fine for GMS2
Pro Highly customizable IDE
Although users must work within the IDE and editor, GMS2 has many options to customize the look and feel
Pro Good documentation
Pro Huge, generous community
Con Not as feature-rich as other engines
Con Small community
Being fairly new on the scene, there aren't much of a community to speak of.
Con Not the best scripting language out there
GML is just weird; if you want to learn programming, it is not the best because it teaches bad habits and has many odd shortcuts and shortcomings that won't transfer to a real language
Con HTML5 export is buggy, doesn't "just work"
Con Quite expensive
Windows ($100) + HTML5 ($140) + Mobile ($400) + UWP ($400) is $1,050, plus $800 anually for each console export separately. But doesn't do anything any of the free engines can't do, and the stability and tech support aren't great.
Users frequently report crashes and hangs, particularly when working with assets, and the software uses a complicated underlying meta-file structure that may become corrupted and cannot be rebuilt
Con Limited support for OOP
Con Small development team
The core programming team is only 5-10 people, with about 30 employees total, so bug fixes can take a long time to be addressed, and there aren't many official tutorials