EDIT: You may consider pre-equipping the sword, or at least warning others that they have to equip it themselves. Cheap death #1 came from that.

Whoops. Yeah I should do that.
Cheap death #2. Your algorhythm, for one whole game, generated nothing but single-wide downward passages with intermittent critter rooms. Wouldn't be bad, if not for the fact that it generated NO food (within reach?), and 2nd floor was littered with mines and spike traps, and no way to maneuver around them at all.
I do let the spike traps and land mines appear along the main path; however, spikes can be chopped away and if you try dropping something on the landmines, they will blow up. Presumably, you should have at least 1 item on you. If not then you're screwed. But yeah, I really don't like the settings I put on some of the floors. The ones that end up as long corridors are kinda boring.
And either your RNG really hates me, or your berries all have 100% poison rates. Whether intentional or not. Even different types of them in the same game. Finally, it's rather insulting that the little basic slimes begin both with more HP than you, and doing more damage. XD Finally, either energy should drain slower, or food should appear more often. About 200-300% either way, if you expect the playability of that to even out. I did supposedly do a fire sword upgrade, but no effect seemed present.
There are 2 types of berries. They both have similar names and colors to confuse the player. The lighter colored ones are the poisonous berries while the dark ones are just fine to eat(last time I checked.) Just a little good-natured player abuse.

I suppose I'll add some kind of more significant indication of the upgrade effects. The element stones will change the weapons element which will cause it to do double damage against monsters that are weak against it. I'll add a more significant indication of the effect. The stones also allow you to charge the weapon for a magic attack that costs 10 energy. You can also use the stones as expendables to perform a powerful magic attack.
Thanks for the feedback! Definitely a lot of stuff to work on!