This weekend (Oct 11-14th, 2018), AppGameKit is available on Steam as part of their Free Weekend offer. This enables you to download and use the AppGameKit game engine as if you owned it, at least until Sunday night. AppGameKit is an interesting cross platform two tier game engine that does 2D,3D, AR, VR, etc. The Tier 1 is a lower level C/C++ layer, that provides functionality similar to SFML, SDL or RayLib. The Tier 2 engine (which is featured on Steam for free), is a higher level BASIC-like scripting language and editing environment that makes developing and testing games easy. The Tier 1 portion of the engine is not included as part of the free weekend.
If you want to learn more about AppGameKit, check out our earlier Closer Look review. Keep in mind, a lot has changed since that review was written, but it will still give you a pretty good idea of what to expect when working with AGK. If you are interested in trying out Augmented Reality (AR), we also have a video tutorial showcasing how to do this using AppGameKit available here.
In addition to being available to try for free this weekend, AppGameKit is also currently 70% off on Steam.