Student or Learner
Please tell me if writing about the launch of futuristic online game I can use in the title 'on the horizon' and say:
The official launch of the Space online game to come on the horizon
The official launch of the Space online game on the horizon.
The usual idiom is:
1. X is on the horizon.
So in your example,
2. The official launch of the Space game is on the horizon.
However, there is an incongruity in the combination of "launch" and "on the horizon" here: if we look at the literal meanings of both metaphors, a "launch" generally takes place from land, whereas "on the horizon" tends to refer to the point (far out to sea) where the sea meets the sky.
Not a professional ESL teacher.