The campaign difficulty level is kinda mixed up - lvl1 chars shouldn't be able to survive tadpoles, let alone escape from hell!
I mean, we don't so much "escape Hell" as we follow the nice Mind Flayer's instructions while he and his army of thralls fight off the armies of Hell for us. All we do is pull a squid-lever.
And even then we would've died if not for our mysterious benefactor.
In other words the DM tailored the encounter to ensure we'd survive. This is incredibly common for 1st level adventures because 1st level characters are like wet paper bags.
