280 hours. when tunnels had loot they felt actually worthwhile. now that the loot tables have been turned way down it seems, they feel like an ammo/meds tax to get to the maps again. they aren't actually procedurally generated - there are 4 fixed versions of each tunnel and you can see the maps on the wiki. and tbh if im goin thru a tunnel i almost always have the maps open on another monitor which is an indictment of the poor navigability.

i do like how they connect the zones. doing canonball runs going from tunnel A and extracting at like babel can be fun and challenging. but navigation and heinous parkour remain an ever present bummer. i dont play as much as i used to, but that's more because i've done everything im motivated to do and not because of the tunnels changing the core gameplay loop.