The Room video games are among the most satisfying things you can play. They’re all about figuring out how to unlock intricately-locked boxes—or locked stoves or locked model submarines or some other beautifully intricate piece of old-fashioned gadgetry. The newest one, The Room: Old Sins, came out last week for iOS. It’s great.

Kotaku senior video producer Chris Person and I recently live-streamed a small section of the game. You can watch us poke at the game and eventually solve a series of puzzles. We were a little lost at the start, so skip the first four minutes if you want to get to the proper puzzle-solving.

If you’ve played any of the three previous Room games, this new one should seem familiar. You’re still tapping and prodding and figuring out how to open things. You’re still picking up the occasional inventory item which itself might be a locked box that turns into a key or something. You’re still using a magic lens to read secret messages and unlock even more locks.

I had played the game for a couple of hours before the stream and have since played an hour more. I’m taking it all in as slowly as possible, savoring each unlocking victory. The newest thing in what I’ve played so far is that you are no longer simply going from one chapter full of lock-box challenges to the next. In Old Sins, you’re uncovering rooms in a dollhouse, zooming into those rooms to solve the many lock-box puzzles in each but also often having to juggle solving puzzles in more than one room at once. For example, you might figure out how to unlock an item in the Curiosity Room that helps you then unlock something in the Maritime Room, which then may help you progress in solving puzzles in yet another room. You’ll see that dynamic in the video of the stream embedded in this post.

The Room: Old Sins is never crushingly difficult. It’s fine for solo play, though a bit more fun if you play with someone else nearby, so they can suggest solutions, too. I’ve enjoyed all of the Room games so far and am pleased to see that Old Sins not only is as good as the previous games but may even turn out to be better. The game is iOS-only for now, though previous Room games have eventually come out for Android and even to PC.