@FlashFrozen: Feel free to do whatever you want with it, it's your design
Basically, all I wanted to do on it was resolve the lighting to be properly unidirectional; the omnidirectional lighting on the panel edges feels very flat atm and there were a lot of areas where relative height wasn't clear to me, making what feels like a very complex combination of gently-curved hull panels and flat areas feel indistinct; adding a bit of lighting to cue the eye to the changes in relative height helps break up the shape without creating more noise. Stuff like the shadow from the conning tower also creates a much stronger sense of height.
If you want to keep it omnidirectional, another pixel of padding on the interior and a slightly raised level of brightness might be appropriate, or just sink them into the hull with an outer dark rim of one pixel, establishing the edge transition. I felt that adding the lighting there might have raised those panels more than you were aiming for, but I wasn't quite sure which way you were wanting to go with the forms so I just picked a way and went with it, lol.
Generally, I find that trying to make the light omnidirectional just doesn't work well; it tends to flatten detail a lot and you don't get the big sense of height; it can also unduly create noise.
I also wanted to balance the engine mass a little better; the way you shifted the engines worked better, but there was a hole in the silhouette on the right that felt like it needed something, so I added a few pixels there to resolve it
I also shifted hues a bit, so that the warm / cool contrast was a little more established and I picked out a bunch of little hull details that were so subtle that I had trouble seeing them until zoomed in. While there's a lot to be said for decreasing noise where it's possible, some sharp contrasts really bring out those things and if it's not overdone it doesn't distract the eye from the forms
Anyhow, that was just my take / thoughts on the changes. I didn't want to screw up your design, which is really strong, while resolving the details in ways that helped make the many details flourish
@Ryxsen: That's really quite good, the design's great; definitely the strongest sprite you've made thus far
The panels could use a bit of edge lighting in places to help establish them, and the engines feel a little flat- a stronger gradient on the tubes might work. Overall, that's a really strong design and if I have any complaint, it's that it'll need a strong built-in weapon or three to be roughly competitive with Vanilla frigate designs