You can go back and read the original easement grant but I would be surprised that it would make any provision for compensation for the temporary loss of your children's play area.
As for restoring the surface to it's existing condition, it would seem that they are offering to do that. You are most likely dealing with a perpetual utility easement and you will be held to the terms of it and the interpretation that Ohio courts have found over the years.
I can assure you that the gas company is not going to have your yard torn up for 2.5 months. 2.5 days would more typical, and unless you have a very large yard 2.5 hours might be closer.
Is the gas company a large operation such as Columbia Gas or are you dealing with a local county co-op?
Is it a major transmission line (say 6" or larger) or are we dealing with a 2 or 4" line?
Any more information you can give would help me advise you in a better way.

