When comparing GameMaker: Studio vs Rainbow, the Slant community recommends GameMaker: Studio for most people. In the question“What are the best 2D game engines?” GameMaker: Studio is ranked 11th while Rainbow is ranked 71st. The most important reason people chose GameMaker: Studio is:
GameMaker: Studio is incredibly easy to learn. It requires almost no programming knowledge which means that those without the technical experience, such as designers or artists, can create their projects without the help of a programmer.
Specs
Question Ranking
Pros
Pro Extremely easy to learn
GameMaker: Studio is incredibly easy to learn. It requires almost no programming knowledge which means that those without the technical experience, such as designers or artists, can create their projects without the help of a programmer.
Pro Gives developers access to a more fine-grained controle over the logic through the Game Maker Language
Game Maker Language (GML) is the primary scripting language that is interpreted similarly to Java's Just-In-Time compilation used in GameMaker. It is used to further enhance and control the design of a game through more conventional programming, as opposed to the drag and drop system.
Pro Easy cross-platform shader support
Write your own shaders in one shader language and have it automatically ported to all platforms. You can even choose a specific shader language to wield the full power of the target device.
Pro Easy to find resources/tutorials/assistance
GameMaker: Studio has a huge following, tons of people put up tutorial videos, and it's just generally easy to find help. It has a huge community.
Pro Extremely stable
GameMaker: Studio has been around since 1999 and has been used and maintained during all this time. This makes it an extremely stable game engine.
Pro It has an IDE used for loading all of the assets
It is very easy to manage all the resources you want to put in your game, the UI widgets for each assets (sprites, sounds, backgrounds, rooms, objects and shaders) are intuitive enough for when adding or even editing the properties of each your assets. The included editors are also good and easy to use (sprite/image editors, shader editor and room editor).
Pro Assets can easily be found in the official marketplace
Yoyogames website has a marketplace which opens up an opportunity for people to sell or giveaway created assets and resources (sprites, scripts, sounds, extensions, full source codes, etc.) for use in GameMaker. This benefits people who needs quality assets for their games, and for creative people to provide these assets for extra income. The Marketplace has a rating system so it can eventually increase the quality and competitiveness of the assets submitted.
Pro Cross-platform
GameMaker: Studio projects can be deployed to: HTML5, Linux, Windows, OS X, Windows Phone, Android, iOS and PS3/4/Vita.
Pro Cross-platform multiplayer support
There is the possibility of creating games that interact with different platforms and is not that hard.
Pro Easy to use
Game Maker Studios simple interface allows for rapid prototyping, and easy development.
Pro Supports 3D
There is also 3D support that doesn't interfere with the primary 2D focus.
Pro Open source
Distributed under the MIT License.
Pro Written in modern C++, is scriptable in Lua
Pro Cross-platform
With support for Android, iOS, Linux, Mac OS X and Windows.
Pro Optional FMOD audio engine
Pro Supports Spine
Pro Physics
Box2D integrated with Lua bindings.
Cons
Con Exporting to some formats costs extra
You need to buy extra modules to be able to export to platforms like Android, iOS, HTML5 and others.
Con No built-in refactoring tools
There are no built-in refactoring tools - for example, you can rename a resource, but GM:S will not automatically change the mentions of it across the code to the new name. At the same time, however, all file formats are text-based, meaning that the effect can be achieved by simply doing "find & replace in files", which is a feature offered by pretty much every external code editor nowadays.
Con The scripting language used is quite limited
Language does not support actual objects, structs, real data types, functions, overloading, even argument naming. Developers generally have to code around the lack of these features in very tricky ways.
Con The cost to buy for development is outrageous
The cost for this tool is hindering for indie developers who have little money to work with.
Con Poor level editor
No marquee select, no layers, can be glitchy, no grouping, etc.
Con Tends to crash or not compile games properly
Con Destructive DRM
In late 2012/early 2013, YoYo Games released a version of their new Studio IDE for cross-platform development that would import games and destroy all of the image type resources for some legitimate purchasers of the software by superimposing a pirate symbol on top of the image. This was due to a fault in their digital rights management software implementation which they use as a method of combating pirated copies of the software. Though the false positives bug is reported to be fixed, the DRM is still in place and may affect placeholder graphics, etc. YoYoGames publicly stated they would remove the DRM at a later point in time, but that other less-invasive DRM techniques would remain.
Con Development has been and will be cosmetic
The change from 1.x to 2.x was cosmetic, the engine and language stayed the same. The roadmap for future development is also cosmetic and includes updating the sprite editor, adding an audio editor, and adding a "mini map" for the IDE.
Con Expensive for what it offers
There are several options with more flexibility, better learning resources, and a lower price point.
Con Proprietary language forces expensive "lock in"
Because it uses GML, a very non-standard custom language, new users do not learn a transferrable language and become locked in.
Con Can't embed videos in game
Doesn't support embedding videos in a game.
Con Bad history of ignoring critical bugs
In the past, the developer failed to update the software for iOS and Android when game-breaking updates were made to those platforms.
Con Doesn't support the Switch
Console exports do not support the Switch. (Update: support for the Nintendo Switch is coming)
Con No GUI editor
The GUI must be hard-coded, leaving a lot of tricky calculations and jumping through hoops to accommodate different devices and displays; it's probably the least developed and hardest thing about GMS2 compared to comparable engines
Con This is very flat for games
They are not beautiful, for example, Undertale.
Con Owned by a gambling company, Playtech
As opposed to other engines, which are open source or owned by game companies, GameMaker is developed by YoYoGames, which is owned by Playtech, a gambling software company.
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.