Sprites Need some feedback on these Undertale Weapon Sprites

[Praygon]

Hey everyone.
I'm fairly new to sprite work and while I've got the basics down i find im hitting a brick wall with creating more detailed sprites most of my stuff comes off kinda flat. I made these Undertale Weapon sprites for practice and id love some critique on what I could do to improve. Also while these are a WIP feel free to use them if you want. (also please note if you haven't finished Undertale the following sprites contain mild spoilers)



Asgore's Trident (Plus a blue and orange attack)

Undyne's Energy Spear

Metatton's Leg (ohhhhhhh yessssssss)
Final bosses sword (I think this one turned out the worst, trying to work with those awkward angles really messed with me)
Mini Metabots

The stick.
Toy Knife (I tried to give this one a plastic look)
The Real Knife (This is the one im most proud of but as with all the others feedback would be insanely helpful)

Also Made this little sprite to try practice poses but again I feel like it could be much better.

Currently working on the rest of the weapons which ill post as I go. Iv made a few other trash sprites just as practice but these are the first real semi decent one's iv been able to make and im eager to improve.

Thanks for your time.

 

[Psycoris]

I like them the lines are crisp for the angles, One thing that stands out that could help the flatness is highlights and shadows, I think that is why your real knife looks the best is the contrast between the blade and the details. If you can bring that contrast to the other sprites it would help liven them up.

I am a fan of the glow on the Undyne's spear though, very nice.

 

[Tazzan]

I NEED THESE! THESE ARE AMAZING PLS GIVE THEM TO ME!!!!!