(which doesnt appear to have any type of gifting...one up on steam?)
Impulse does support gifting, but it must be done at checkout. If your friend did not explicitly purchase the game as a gift, it will have linked it to his email address and that'll most likely be the source of any issues with the registration or in-game login. As spooky noted, support should be able to figure out where things at at and get them put in the right place.