Buy Vortex Attack Retail LIMITED edition (Copia física) , using PayPal:

19.99 € (Includes delivery to Spain and packaging)
Contact us if you want it to be sent to your country.

Includes:

– Vortex Attack Retail Version
– Includes Latest version for Arcades and Standard.
– Instructions flyer
– And quite a few extras on the same disc.

But , if you just want to play through STEAM:

A – Pay through from Steam:
http://store.steampowered.com/app/357890/Vortex_Attack/

B – Pay through PayPal:
Steam KEY discount -33%:
5.25 US$ / 5.25 € / 3.75 £

C – Pay through GreenMan Gaming:
https://www.greenmangaming.com/games/vortex-attack/