Yes, the well-known construction kit for a 35 mm TLR, here it came from Franzis as an Advent calendar (nice idea, especially in December), but it is also available as common set, and also from Somikon or Pearl, it is also known as "Gakkenflex". I made 24 pictures of what I've found behind each door.
The result is really nice and I don't think it's an optical catastrophe.
The frame size is 24 x 36 mm and portrait-oriented, and there is a tripod bush for landscape orientation. The film advance is of course very simple, but clever: the camera doesn't lock the advance wheel automatically (would be much to complicated), but you have to observe a rotating ring, which gives you an indication of the film transport (which gives you also the opportunity to count the frames by yourself). There is no rewind lock, you can rewind the film at any time, like on an old medium format camera with roll film. Needless to say, that there is also no double-exposure lock, which brings us to the shutter: only one speed (and no B-setting), the data sheet says it is an 1/125 s, but I have my doubts. The shutter consists of one, relatively heavy blade and I assume the typically 1/30 to 1/60 s for it. The shutter is self-tensioning and there is no thread for a cable release. The two lenses for capturing and focusing consist of one piece each, and even if they are plastic made, they are looking very trustworthy. Behind the taking lens is a ring, acting as aperture of f/11. You can remove it, then you'll have f/5.6. In my opinion the focal length is 50 mm. It is not a fix-focus lens, you can set a distance from about 50 cm (probably less) to infinity. You must use the viewfinder for focusing because of the lacking distance scale. The two lenses are coupled with tooth wheels, like on a Russian Lubitel 166. Opening the hood of the viewer is really painstaking, there are no springs which help you, you have to raise up every part separately. The quality of the viewfinder is not that bad, I've seen worse. Some people are reporting, that they have found a transparent plastic pane in their set instead of a ground glass, which is unusable of course. Not here, the provided screen is okay. You can't see its grain anyway, because there is no viewer loupe.
Helpful tools for assembling are a longer screw driver (size PH 0), some pointy tweezers for hooking the springs of the shutter and a paper cutter for removing the protection sheets of the mirror and the sticking pad. As extras the set contains a lens cleaner (ha!) and a tiny spirit level, but no film and no neck strap (like shown on the box). The German instruction booklet is okay, though it could be more explicit on some steps. Some experiences in servicing cameras are useful, e.g. mounting lenses and mirrors without leaving fingerprints. Ah, one door revealed a voucher for a book download: "Think Analog". Hm.
The quality of the plastic parts is good, they are deburred well and they all fit together. I haven't tested the camera yet, so I don't know about trouble with light leaks though.
The assembly of the shutter needs some attention. It consists of mainly three parts: shutter blade, release lever and a transmission lever. Each of them is attached with a screw, and the proper function of the shutter depends on how tight you fasten those screws, you probably have to test a lot until it works fine. Annoying on my copy: after covering the shutter with the next part, its behavior changed a little bit. Before the shutter opens, you'll have to get over a resistance with the release lever, which means you'll shake the camera automatically. The only remedy I found is to move the release lever very slowly: first get over the resistance (dull clack) and then open the shutter (high-pitched click). Not very satisfying, but perhaps a good idea anyway. While toying with the camera I have found out, that you can open the shutter like with "B", when you move the release lever back after the first dull clack - with some exercising.
I'll check the infinity position of the lens yet, and then perhaps load a film ..