Suitable for kids? I guess so. But the movie is pretty unconventional.
It tries to capture and deliver the long-forgotten atmosphere of soviet childhood with many of its supporting characters based on nearly iconic characters of old Soviet cartoons and children's stories. The setting - Moscow of the 60-s. This contributes to the overall spirit of nostalgia, It's like if the authors take their old toys from an attic and start telling their stories.
The story is little sad, and the characters always have to keep struggling, while their fate doesn't even belong to them. This spirit is probably created intentionally to make the viewers experience what it was like to be a Soviet man. There's nothing propagandistic about this film, and, as I said, It feels very authentic.
The original Russian voice acting plays an important role in delivering the spirit, which is often even more important than animation itself. I do suspect the dubbing doesn't contribute to correct perception of this piece.
Overall, this is not exactly similar to Pixar movies and it's not about a positive message, fun or enthusiasm. But it enables viewers to experience, like, an ancient civilization that no longer exists.
What it reminds me is "LES TRIPLETTES DE BELLEVILLE". However, "Space Dogs" does seem to be acceptable for little kids and has some humanistic messages to deliver. Only that it's not about walking around and making the world a better place. It's more about facing things that are not in one's power to change at all.
That said, the pace is quick and action-packed, so it's hard to get bored. Overall, a good first step towards Pixar standards.
The quality of CG is not exactly up to modern standards, but it's advantage is about delivering the spirit of Soviet puppet-animated films. So I say it's good, as I doubt anyone else could do it.
So, why is this worth watching for a non-Russian-speaker? I guess it's like anime - another world, another life philosophy. It's also educational.
It's not very good for those who: a) expect a charge of purely positive energy and uplifting messages b) have a particularly strong bias against USSR
