Well I'm fairly new at this Pixel Art thing too, but I can tell you right off that your colors are way too bright/saturated it looks like your using MS Paint's color palette. There are some really helpful topics here that discuss the finer points of proper color selection and palette choice.
The walk animation is definitely terrible lol...I would suggest looking up some simple walk animation tutorials. There is a good one here on the forums http://www.wayofthepixel.net/pixelation/index.php?topic=12983.0
Can't see the images
I see you talk about a clock but, where's the clock? : ?And yes, the enemy sprites could use some work..The rats are almost invisible on that dark background, and the eye is so messy!
Mmm, that doesn't look much like a clock, where are numbers and hands? : o is it 'cause it's WIP?
...So, what exactly is the perspective? It looks like the first few are top down and the last is sidescrolling, but the top down ones have everything facing the camera.