It's a lot better than I could make.

To me it looks like the style of Monkey Island game.

Can't say much more, not an artist.

Overall they look pretty good!

Just a few things I'm not sure about: Are the images you posted native resolution? If not, could you post the originals? The don't look quite pixel-artish enough to be really 16-bit, although if that's an issue depends on your goals.

The major artistic weakness is that the shading/lighting isn't distinct. You have stuff sort of shaded, but there's not really a light source. This is especially problematic for the guy with the plank since he's one texture and therefore looks formless without directional shading.

I took the liberty of quickly splashing some shading over the plank guy in Photoshop to show you what I mean:

[attachment=13027:MOnsterShaded.png]

Edit: swapped image formats

[quote name='Got_Rhythm' timestamp='1357109185' post='5016589']
do you have an idea of how I can make it look a little more like a log instead of a flat plank?
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If it's a cylinder, shade it like a cylinder. A band of shading running the length of the log, opposite the light source, but not fully reaching the bottom since, as a round object, light will wrap/spill around a bit from the opposite side (see shading spheres, cylinders, etc)

Also, cap it with a circular end at some point. Even if the snapped/damaged bark extends past the cap, it helps to show form. Barring that, make sure his hand looks like it is grasping something circular.

It looks like your images are resampling from scaling, thus creating the slight feathered look between pixels.

If you want to get a more crisp pixel look, use an indexed color format. This will preserve the color value in the pixels.

Also, if you're using Photoshop, you can change the mode to indexed under the Image menu, then scale down and back up to get a nice clean retro look. If you're using something else, I suggest using PNG to help retain the lines but you'll have to always work in png cause if you go to jpeg, it'll get all f'ed up.

Aside from that, I gotta agree that you could work on the shading to help create depth, scale, and breathe life into your sprites.

But yeah, all that being said, I'd say they look alright. They could use some work, but they're a good start.

Well for my version I used the dodge/burn tool but I wouldn't recommend that since it affects the pixels of a layer directly. I would instead make three new layers:

1. Mask- this should be a layer to hold a layer mask the same shape as the sprite so you can draw outside the lines and it won't disrupt the background (good for keeping a solid background)
2. Highlight (Mode should be "Screen" or similar) to hold white pixels that lighten the underlying layer (like your current characters)
3. Shadow (Mode should be "Multiply" or similar) to hold black pixels that darken the underlying layer.

Note that the colors don't necessarily have to be straight black or white, just lighter or darker, and you want to be putting down semi-transparent pixels, probably with like a 7-15% pencil tool.

One other method for adding shading fast in Photoshop is to use Bevel and Emboss under layer effects- but that's really cludgy since it can only follow the outline of a layer, so to use it you'd have to separate everything that overlaps within the sprite into different layers. And even then, it would still look funky.

As for the plank/log problem, BCullis is right, it's all about getting a handle of how to shade basic shapes. Here's a thread of someone having pretty much the same problem: http://www.gamedev.net/topic/633482-why-does-this-look-so-flat/. You should also look up some shading exercises, or even invest in a drawing book since the basics carry over regardless of medium. I have this on my desk right now and I refer to it pretty regularly.

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For the Head in particular, I don't really remember anything super specific... I made sure that I shaded under his jaw and the left side of his head to his shoulder (the shadow cast by his head on his shoulder). I also highlighted the right side, since that's in my imaginary light source.

[attachment=13057:PlankGuyHead.PNG]

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Bonus:

I never messed with index color like Dave Troyer was talking about, but here's what it can do:

[attachment=13058:IndexedColor.PNG]

Looks like it makes you collapse your layers, but it will dither for you, which is pretty sweet.

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As a final note, it doesn't look like your sprites are really pixel art (although that depends on how strict your definition is), since it looks like you're blurring/adding texture without manually manipulating the pixels. That's a whole other topic though.

Edit: Let me know if you have any questions, I should be able to respond tomorrow although anything in depth will have to wait for the weekend...

Good luck!