Very nice idea. The general vibe and the models are very nice, and quite impressive to make a nice-looking 3d game in 4 days. My one critique is that getting dropped into such a large first level is a little overwhelming. It would've been cool if the levels got bigger and more intricate, instead of starting out that way. The rail network in the first level is already quite confusing, so it would've been nice to be eased into it. But otherwise a super solid entry.