Wow your getting better.

Keep at it! You'll do great!

My only advice is to start small and Google some tutorials to start getting a basic understanding on whats happening. Another thing to do will be to study the art of others and see how they apply the principles of pixel art.

Anyway,

Good Luck!

Thanks mate, I have been reading some long tutorial on spriting and the basics of it, too bad there isn't anything about slimes in there

I'd recommend a more top-down lighting scheme - otherwise it is going to look unnatural when you have to flip the sprite in-game, and it also makes the form of the slimeball very hard to read.  Even given the basic shape of your slime ball, the way you have shaded him makes him look like a flat piece of clay, rather than a round piece of slime!  I think you need to do some research - look up pictures of slugs and frogs and things, to see how slimy things actually look!

Hi, about the top down lightning scheme, it luckely is't nessisary. I have been looking up on some pictures about slugs and frogs and I noticed that the lightning reflected is almost  always pure white except when its a colored light.
Thanks for the advice

I don't have time (nor talent) for an edit but I found a good reference which could help you while shading :

Thanks , nice pic to research lightning for me

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I've tried to apply the lightning on my slime but I am not totally sure it worked out. But it definatly looks more slimey now

I see what you mean , the shade there looks very unnatural, I am working on a better shade and update this post asap with it.

EDIT:

I made 4 different edits, but its weird imo the second shade seems to fit best .. hehe maybe it wasn't such a good idea to start with a slime but o well now that im at it ill finish it

Ok I reduced the size a bit (and destroyed the whole inner core idea as it was getting annoying )and did the coloring and tried the AA not sure if it totally worked out but I like how it looks now

Thanks mate , that looks very nice , since its not a boss monster I guess I can make it a bit smaller ,  but the resolution is 800x600 for the game so I won't make it that much smaller, and now that ive seen your edit it seems I did get the shading out quite ok, except that the colors were kinda off 

Thanks for the critique, ill try to apply and remove the things youve said.
But its odd , the place where I made this sprite the dark green wasn't so dark at all, but now that I am at home its almost black, anyone know if this is the cause of the system or the monitor, or both?

And  No. 2: Pure white and black are very bad and eye cancer inducing. , is this like for real or just a joke?.. I hope a joke :/