The kickstarter for this is closing in 10 hours and there's some doubt if the 500k stretch goal will be unlocked. The publisher has just promised that if the kickstarter doesn't break the goal they will offer it for sale and include it for free in the immortal (all in) backer level.
Ares Games wrote:
It's actually quite simple. IF we don't reach 500K, the Hellspawn would be an add-on. That we cannot avoid. BUT we can make it FREE OF CHARGE to IMMORTAL backers (add-on and pledge). So if you are already at $195/$199 - no worries. Your all-in pledge remains all-INCLUSIVE. If you are not... you can still get the Hellspawn as an add-on (probably, a $ 15 add-on).