Opening paragraph— you present a band of characters who are self-aware or their nature. This could be interesting if you pull it off right.
Is Alicia and Allicia the same person?
This is expository: "The spells of this type provide additional information about the enemy." It states explicitly what can easily be inferred from the context, and drags the narrative.
You have choppy sentence structure. One example: "The boss also summoned minions—skeletal warriors and shadowy wraiths—emerging from the darkness. But they were cut down by the party’s silver-rank damage dealers" this should be one sentence with a comma. Think about a rhythm, where each sentence carries a beat. You'll want to vary your beats so that it doesn't get too monotonous.
In keeping with the gameified nature of the narrative, you bypass the five-senses almost entirely. There's some visuals, but even these are scant. For example: "a barrage of arcane bolts" (factual, non-sensory) could be written as "streaks of blue light crackled through the musty air" (sight, sound, and smell). Obviously you don't have to write it this way, but you need to find something to draw your audience into the world.
It starts to heat up when the boss monster comes back to life, but before that there's no conflict. Most readers are going to quit before they get to this point. One way to overcome that is by introducing the conflict in the beginning and then tracing out how they got there. Hunger Games does this—starts off with "today was reaping day" which sounds dark and ominous, then goes on to describe her family and feeding entrails to her cat, and you end up several pages in before she explains what reaping day is.
"Complete panic set in among the party" show, don't tell. I felt the panic growing earlier, keep that up. That whole paragraph is expository, please get rid of it.
After the party dies, it wouldn't be out of place to say something about how many lives they have left. That's what I would do. Your story. Ignore this comment.
Also, you have chapter 2 twice.
It seems Alicia is your MC. It took way too long to figure that out, and there's no character development. Who is she and why should I care about her?