author: Astrid S. de Wijn, license: CC-BY-SA 3.0
icon11.png
iconBase.png
arrow*.png
stunBolt.png
*Dir.png
sellIcon.png
buyIcon.png
gameover.png
explode13.png,explode14.png,explode15.png,explode16.png
icon1.png,icon2.png,icon3.png,icon6.png,icon7.png
explode9.png
explode10.png
explode11.png
explode12.png
explode1.png
explode1.png
explode3.png
explode4.png
elec*.png
chainLink.png
cursor.png
smallFont.png: monospace bold 13 pt (gimp)  anti-aliasing is off.
targetText.png: same font, smaller, anti-aliasing on
gameover.png: 72pt
icon8.png
plasmaGreen.png
plasmaRed.png

faces except kline: CC-BY 3.0; author: Antifarea
face_chris.png http://opengameart.org/content/48x48-faces-2nd-sheet
face_phoebe.png http://opengameart.org/content/48x48-faces-2nd-sheet
face_sid.png http://opengameart.org/content/48x48-faces-2nd-sheet
face_ursula.png http://opengameart.org/content/48x48-faces-2nd-sheet
face_crew.png http://opengameart.org/content/48x48-faces-3rd-sheet
face_krass.png http://opengameart.org/content/48x48-faces-3rd-sheet

face_kline.png: CCBY 3.0; author: Antifarea, remixed by Astrid, combination of http://opengameart.org/content/48x48-faces-2nd-sheet and http://opengameart.org/content/48x48-faces-4th-sheet 

planet_sun.png CC0; author: NASA; http://opengameart.org/content/the-sun (reduced in size)

planet_*.png CC-BY 3.0: author: athile ; http://opengameart.org/content/planets-pack-8 (reduced in size)
icon26.png

GPL 2.0 GPL 3.0 CC-BY-SA 3.0 http://opengameart.org/content/astrominer-sprites (remixed by astrid)
drone*.png
tug[12].png
mineBoss*.png 
missileBoat*.png
merc*.png

mine.png CC-BY 3.0 http://opengameart.org/content/iron-plague-minebmp
transport*.png CC-BY 3.0 http://opengameart.org/content/iron-plague-cargo2bmp
dualFighter*.png http://opengameart.org/content/iron-plague-hunter1bmp
mobileCannon*.png http://opengameart.org/content/iron-plague-ship4bmp
aimFighter*.png http://opengameart.org/content/iron-plague-doomdaybmp
barrier.png http://opengameart.org/content/iron-plague-beacon2bmp
wingmate*.png http://opengameart.org/content/iron-plague-bshipbmp
evilUrsula*.png http://opengameart.org/content/iron-plague-bshipbmp
rebelCarrier*.png http://opengameart.org/content/iron-plague-cargo1bmp
sid*.png http://opengameart.org/content/iron-plague-ship2bmp
kline1*.png http://opengameart.org/content/iron-plague-hunter2bmp
plutoBoss* http://opengameart.org/content/iron-plague-factory2bmp
splitBoss* http://opengameart.org/content/iron-plague-factory2bmp
mobileShield* http://opengameart.org/content/iron-plague-warpbmp


cloakShip*.png http://opengameart.org/content/battlefront-operation-x-final-striker
goodTrans*.png http://opengameart.org/content/ship-recoloring-001-for-gm-game

escort*.png http://opengameart.org/content/spaceship-360

explode0*.png CC0 http://opengameart.org/content/explosion, resized

asteroid1.png: public domain ; author: NASA ; http://en.wikipedia.org/wiki/File:571423main_pia14316-full_full_Vesta.jpg (21 Lutitia)
asteroid2.png, asteroid3.png: public domain ; author: NASA ; http://en.wikipedia.org/wiki/File:571423main_pia14316-full_full_Vesta.jpg (253 Mathilde)

startUp.jpg: public domain; author: NASA (Hubble space telescope) ; http://hubblesite.org/gallery/album/galaxy/pr2009014a/

achtergrond*.jpg: public domain; author: NASA (Hubble space telescope)  (cropped and curves modified)
achtergrond1.jpg/eyananth.jpg: http://hubblesite.org/gallery/album/nebula/pr2009025e/
achtergrond2.jpg/mordor.jpg: http://hubblesite.org/gallery/album/nebula/pr2006001q/ 
achtergrond3.jpg/spirit.jpg: http://hubblesite.org/gallery/album/star/pr1992029a/warn/npp/all/
achtergrond4.jpg/sol.jpg: http://hubblesite.org/gallery/album/star/pr2007004a/npp/all/
achtergrond5.jpg/credits.jpg: http://hubblesite.org/gallery/album/nebula/pr2005012b/

ore*.png: public domain ; author: NASA ; http://en.wikipedia.org/wiki/File:571423main_pia14316-full_full_Vesta.jpg (243 Ida), modified by Astrid
 
frigate*.png, execTrans* GPL 3.0 CC-BY-SA 3.0, Skorpio, http://opengameart.org/content/spaceships-top-down, remixed by Astrid
miner*.png slaveTrans*.png http://opengameart.org/content/spaceships2-top-down

icon5.png,firefly*.png CC0 http://opengameart.org/content/top-down-space-fighter-sprite

GPL 2.0, GPL 3.0, CC-BY-SA 3.0; Ails, http://opengameart.org/content/420-pixel-art-icons-for-medievalfantasy-rpg remixed by Astrid
icon23.png
icon16.png
icon17.png
icon15.png
icon10.png
icon12.png
icon14.png
icon9.png
rocket.png
superCharge.png
cargo1.png
plasmaDamage.png
plasmaAmmo.png
plasmaRate.png
heart.png
dollar.png
pod.png

CC-BY 3.0 CC-BY-SA 3.0 ; OceansDream http://opengameart.org/content/various-inventory-24-pixel-icon-set, remixed by Astrid
icon18.png
icon19.png
icon20.png
icon22.png
icon24.png
icon25.png
rocketAmmo.png
icon13.png
rocket[12].png

public domain http://en.wikipedia.org/wiki/File:DIN_4844-2_Warnung_vor_Laserstrahl_D-W010.svg , remixed by Astrid
icon21.png

old data:
prlogo.png
sflogo.png
alienDevice.png


icon4.png CC-BY-SA 3.0 http://opengameart.org/content/floppy-disk, remixed by astrid

CC-BY-SA 3.0 http://opengameart.org/content/spaceships2-top-down
eliteFighter*.png 

All GIF and BMP images have been converted to PNG. PNG and JPEG files are
optimised using advpng from AdvanceCOMP, and the jpegoptim utility.