ddp = dodonpachi.. so yeah
it's explained in the description of my other ship

There is a link with the game Dodonpachi created by Cave ?

For me, it's the shape of the ship, as it's just an oblong at the moment. Your other piece had a more complex shape and more details in defining different heights by using darker shades (it also looked much more like a DDP ship). The height levels/layers doesn't really show that much on this particular piece so it looks a little flat.

I'm not to sure how helpful that was, but I still like it

Thanks for the comments everyone..
I totally agree that it needs more detail, weaponry etc.. I just got a little fed up with it because I couldn't get it to look like I wanted. Any suggestions on what to add?
About the background; I gave it a black background since that was the most complimentary. It's supposed to go on a dark background like in ddp.
I guess I'll have to put in a little more work.

Better add some stars to the BG instead of making it transparent I'd say. Adds to the atmosphere. Classic style.

I love the colors! But, as jalonso and stickman mentioned, it could use some more details, some weapons perhaps?

Nice, but not as good as the last one. I also agree that it could use a lot more detail, especially on the actual shape of the ship.

It could use way more details, but its nice. Transparent BG, maybe?