I was having a nosey at the free stuff available on Steam a week or so ago and came across this. It mostly has a load of guns (from 19th Century through to modern day) that you can play around with, but also other stuff like AT Weapons, Artillery, Launchers, Bikes, Cars, Military Vehicles & even Skeletons. When you select a gun you are given a series of 'modes' you run through including:- Field Strip Disassembly Assembly Operation and within these modes you can do things like cutaway & 4 x-ray view modes plus slow down modes so you can see the operation in slow-mo, while also adding part name references etc. For each 'gun' there are some game modes (i.e. strip & re-assemble in the correct order etc) and also a few target ranges (which are a bit gimmicky in my view). No idea how accurate & reliable the actual models & parts are, but they look really good. Also each item has a difficulty rating. So a MkII Sten is considered easy whereas a Flak 88 is considered Insane. Here is a typical example of how things look within the game The game is free to download via Steam, but you only start off with a few items to play around with at first, and have to 'unlock' additional guns/items by gaining experience by completing the modes & games etc. Typically it also has a Pay-to-Play aspect where you can purchase additional exp points or credits, or buy packs which contain a number of guns/items/ranges (i.e. The WW2 pack contains 12 guns & 1 range costing £6.99) There is also a 'Lifetime' Pack costing £29.99 which gives you instant access to all guns (including all future models which they seem to add on a regular basis) and also 10 ranges.