Huh

[GameSpy]

http://www.reddit.com/r/IndieGaming/comments/yrw43/epic_space_game_ships/

[Coppermantis]

Yeah, the flagship sprites are from a stock collection. A few games have used that particular one.

[BobTheJanitor]

Quite a lot of them came from the game Tyrian. The artist released the sprites as public domain some years back. Do a google image search for Tyrian and I guarantee you will see a lot familiar shapes.

Edit: It's kind of amusing that these days the sprites are probably better known as AI War ships than they are for the original game that they were drawn for.

[Coppermantis]

Google search turns up Fighter, Raid Starship, Science Lab, Rebel Bomber, Anti-Armor ship, Autocannon, Space Plane as well as what looks like part of the Zenith Starship. Curious.

Since AI War was originally a one-man development, it makes sense that a lot of graphic content would be freely released stuff from other people.

[Mánagarmr]

A LOT of the art from the first release of AI:War was taken from the open-sourced Tyrian art, and previously unreleased art by the same artist. Also, everything in AI:War is open-sourced and returned to the same repository. For that very reason. So I don't think you actually can "steal" AI:War art, as far as sprites go.

[TechSY730]

Out of curiosity, I just downloaded the OpenTyrian fork of game (and yes, it is a fork, as the developer very kindly open sourced the last 2.x version of the actual game, in addition to releasing the artwork under a liberal liscense), and it is a pretty fun game. The difficulty curve seems a bit steep between the first and second levels, but what the hey, if I play AI war, I don't shy away from games that are tricky.

EDIT: And it is the legitimate sort of hard. When I die, I don't feel like I died because of cheapness, but because I didn't do a good enough job of dodging. Aka, its the good kind of hard.