Interesting question Kevin.
From my personal experience, I think as much as we might not like it, interactive games and (believe it or not) television; are one of the best ways for a child to learn a language, especially in cases where you don't have people around to teach them.
When I was growing up, English was beyond foreign. Because of the regime in SA then, I had almost no interaction with anyone who spoke it except from TV. I'm not sure how I got the grasp of the language by watching the occasional TV programs but eventually when opportunity availed itself for me to go to a 'multi-racial' school, I had caught on so much of the language that it was super easy to have conversations, broken as my English was. A few months after enrolling at the school, the teachers were asking me "Where did you learn to speak English? you speak well" - yet no one at home or in the community had taught me. The medium was English at the school and I did well academically. I'm still convinced TV is how I learnt the language.
When my son was 4, I bought him one of those multilingual laptops in which he was able to learn and recite most of the Spanish words. Then he would watch programs in Spanish. He started talking in the language too but due to not having anyone to speak to, I'm sure he'll forget most of it, so to reiterate what Hummingbird5356 and brainrock said, being fluent may depend on having someone there who speaks the language but for a start, age-appropriate interactive games and TV (because of its visual aspect that helps relay the semantics of the language), are a good foundation to a child learning a new language. You could get them language DVDs for a start instead of pre-determined TV programs.
I don't think it's confusing for kids as long as you they know which person to speak a particular language to or when to speak it. In my home, my son knows we only communicate in IsiZulu, speaks IsiXhosa with his dad's family and English at school but he'll respond in the appropriate language that is spoken at the time. The little ones are generally smart enough to know there is a difference.