Same here. I checked the webpage and it's hard to find any infos about drm in the future. There are some infomation what they want implement next, but nothing to get an idea in which direction they want to go in the long run. A FAQ-page would be nice, unfortunately they say in the video to check the forum but it's only visible if you register and check in. The game looks interesting and it's just 1€, but I'm really careful about early-access games nowadays, too many bets on the wrong horse.
The TUG Kickstarter page (https://www.kickstarter.com/projects/nerdkingdom/tug-1/description
) indicates that the intent is to make the game DRM-free. They also stated that there will be no online requirement and that multi-player servers will be DRM-free and made available for users to run on their own. I haven't followed the game's development, so I don't know if any of those Kickstarter promises (made two years ago) have changed.
Wow, they actually have a minor FAQ at the bottom of that page.
They address both Single Player (yes) and Offline (again, yes).
Single player I can confirm, but the Offline aspect at this point I have to contest.
Up towards the top of the page they indicate it will be DRM free.
While not a huge issue, there was a Registration Key required though.
The game is still on sale for the next couple of days, so I'll dig around and maybe pick it back up if I find out what's going on with the Online bit.