First of all - watching this workshop unfold is a real treat. Thanks and kudos to all the participants, and to Andail for starting this beautiful thing!
Now, to the individual pieces:
Miguel:The monster with the thorn in his side, behind whose hatred there lies a murderous desire... for love. He's not strange, he just wants to live his life this way. No, scratch that, he
is strange. I actually like how thoroughly strange and creepy, yet somewhat vulnerable(in a strange, creepy way) this guy is. I really like the detailed comic book-like penicls as well.
The colours could use some work, though. Try picking more complicated, less saturated colours or just throw a third colour over the whole thing to start tying the piece together. Also, I think you can skip the proper light rendering here and go for a stylized comic book look. I think It could work really well with Moebius(or most other bande dessinée artists) style colouring.
Misj:Everything seems pretty good here so far. I like how much time you're spending on creating and designing the main character - it's more of an animator's approach, and it's interesting to see it in the illustration workshop. The composition is really solid so far too - like the arches and character placement. The only potential problem I see here is the low value difference between the background and the right(her left) side of heroine's body, but I'm sure that'll be fixed with the addition of clothing. Oh, and the other problem is that I just wrote "heroine" and had no intention of changing that - she definitely doesn't feel like a monster. I'm sure we'll find it in our hearts to forgive you for that and enjoy the final result.
dactylopus:There's an action shot if I ever saw one! Good job on capturing the monster's intensity, other than that - keep working on it and always listen to loominous.
cat:Loving this composition! Very striking, effective and energetic. The only obvious problem with it is that it's not very defined and doesn't allow for a lot of extras, so everything will depend on the rendering of large forms and getting the atmospheric perspective(yeah, probably not aerial in this case

) just right. In any case - a very promising start, good luck!
loominous:Always a treat to watch your process. Very much looking forward to seeing where you'll take this, because although it's looking great and very atmospheric already, I cannot at this point imagine what it will look like in full colour.
ProgZmax:Love the epic feel, the lovecraftiness and that it tells a story. It's a pretty ambitious project, hope you'll get it done. Loominous has already covered most of what I wanted to say about this, so I'll just post this edit I scribbled for a thumbnail (Okay, I know we're not supposed to make edits, but it's tiny, unusable and can almost pass as a new thing. I also won't do this again, I promise

).
waheela:What a charming fellow! Seriously, there's something about this character that just grabs me, hope you'll manage to retain that je ne sais quoi in the colouring. Good luck!
nihilyst:Good take on the topic, going slightly beyond simply "huge". Looks interesting and dark and depressing so far.
Mordalles:Ok, this is just awesome. Awesome monster design, awesome details, awesome composition and sense of scale. Another good candidate for Moebius/comic book-style colouring, in my opinion, although the dark painted thing you're going for looks great too. Top marks, really looking forward to seeing the finished piece.
Cerno:Cute! It may not be the best entry technically, but it has plenty of it's own charm - now you just need to find a palette that enchances this charm.
Andail:Really digging the sci-fi setting, the warm, sickly, traditional art feeling of the colour scheme and the upward dynamic here. The monster itself is interesting enough as well, so all that's left is refining it.
So good luck with that, you're going to need it!

[because there's a lot of stuff to paint here]
selmiak:Don't have much to say about this one, except for I'm getting a slight Futurama vibe from this guy.
SookieSock:Excellent, dynamic sketch, especially with the new pose. The colour palette is very atmospheric and harmonious too. Good work so far!
Snarky:It's at a pretty early stage, so it's hard to say anything constructive, but I like the very particular brand of creepiness that it possesses and the choice of the angle is definitely a good one.
Kasander:Really love how energetic and dramatic all your sketches are. The monster is really compelling and well though out, really scary too. Easily the most horrific one of the bunch, but because of the backstory - the one that I empathise with. Also, it made me go through some of the new Swamp Thing comics drawn by Yanick Paquette and that made my day. Thanks for that.
Ben304:I like the design of the demon, but his pose is a bit stiff and nondescript. Coupled with a very backgroundy background it makes the whole scene feel somewhat lifeless and staged. I'm sure you could make it look nice, seeing how that's you, but I feel you should try an entirely different, more dramatic and illustration-appropriate composition for this.

Good luck to everyone who's working on something - all of this is really, really cool! Here, have another cup smiley: