Dark BASIC can produce 2D or 3D games, but I feel AppGameKit is the better tool for 2D work.
Dark BASIC is a Direct X 9.0 (and 10 if you use the upgrade) application development tool; this means it is powered by an industry standard API. Recently the TGC company have been working on the next FPS Creator title, so there will be updates for DarkBASIC because it is the tool used to create FPS Creator.
Million $/£ video games still make use of Direct X 9.0+, note that the current XBox uses Direct X 9.0. and Microsoft will continue to support the Direct X windows and XBox platform for years to come (unlike XNA which will become obsolete).
What this means is what Direct X 9.0/10.0 can do, Dark BASIC can do. Under the surface it is Direct X controlled literally by a BASIC programming language. Some advanced features not available via the standard DarkStudio package and require some C++ plugin work; much of which has been handled for you by a group of developers selling their solutions as plugins; or extensions.
It is quite understandable to question the age of this tool; but age is good; it shows a long period of testing and on going support. There are more advanced engines out there, but that does not mean that they are easy to use.
A thriving community shows that there is support for the tool, there are plenty of tutorials to get you started. Just have a good search in the forum and ask questions.
This news may sound good to you but that does not mean that 3D video game creation is walk in the park, it is still hard work so you can only get out what you put in. If you throw your hands up in the air when experiencing a few 'glitches' here and there and expect to not hit problems, then forget purchasing any game development tool anywhere; 3D video game development is the most intricate and confusing entertainment medium to master.