Recs.
Updated
SpecsUpdate
Pros
Pro Documentation manual is good
Before searching answers elsewhere, you might want to check its program documentation because often times the offline user's manual is enough to introduce you to the development environment, programming functions, tools, etc. that the GameMaker Studio has.
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 Built-in support for pixel-perfect collisions
Enabling pixel-perfect collisions on 2D sprites is so easy many will likely turn it on when maybe they might be better off without it. Regardless, it simplifies small and/or retro console-like game work. This is a feature fairly unique in this class of game engines.
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 to find tutorials, examples, and help
GameMaker: Studio has a wealth of options and a long history of community-based tutorials and examples. The GameMaker Community features these for free use. The program also comes with a number of demos and tutorials. There is also a recently-opened Marketplace which offers free and sold assets for jumpstarting your games. And due to recent growth of YoYo Games, the Helpdesk system is greatly improved and will now be able to send you good, helpful replies to any issues you have quickly.
Cons
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 Code editor not friendly to indented code
While the editor of course has features for intending code such as auto indent and smart tabs that can be turned on or off, these features work in unusual ways and, overall, the editor is not very adaptable to various typing styles. Also, Home always takes you to position 0 and never to the beginning of the text no matter how many times you hit it. Thus, if you hit Home and then Enter a new line, with auto indent on, it will always mess up the indentation on the line following the new line leaving you to fudge around to fix it manually. If you prefer tabs over spaces, forget it. Finally, if you leave the GameMaker app and try to click back into the code editor, the code editor will not fully get the focus sometimes leaving you with the ability to type but not tab. It usually takes two clicks to fully focus the code editor from outside the GM app.
Con No way to activate or use existing modules
Support entirely focused on new iteration depriving even basic functionality of this version with any purchase that hasn't already been activated. It is still possible, thought not intuitive, to download this version on the trail screen for GM S 2. But no purchased (wildly expensive) module can be added any longer.
Con Expensive
Most engines are free; GameMaker: Studio is very expensive ($100 to $800).
Con GML scripting language is proprietary
GameMaker: Studio provides a classical text-based scripting language for advanced users, and this can also be a great way to learn general programming concepts. However, the GML language is unique to it, so language-specific skills are not useful anywhere else.
Recommendations
Comments
Out of Date Pros + Cons
Pro Free for Windows Desktop publication
GameMaker Studio: Standard is available at no cost and publishes Windows games with no license restrictions, though unlike the Pro version, Standard games are bundled with an interpreter rather than compiled to native code.