Quest Cage: City Tunnels

Tunele po miastem (City Tunnels) was an unusual game that lived up to its name. I would absolutely recommend playing it, with a couple of warnings: you need to have good mobility, and you should play it with a small team, two people if possible. That's both because much of the game is physically narrow, but also because there were several highlights that it'd be easier to miss with a larger group. It's atmospheric, fun and different, definitely worth trying.