I did the Michel Thomas Spanish course and I found it to be excellent. It can be a lot harder to stay engaged than a gamified app, but you come away knowing a lot more than you would expect.
Yes, plus I can put it on while doing the chores, which is ideal, same as Glossika as my previous post. It's naturally there embedded into my daily workflow.
Everything else e.g.: Assimil is a workflow interruption, a new habit I have to assimilate, so it becomes a lot harder to do consistently over a long period of time.