As a French native speaker, I'm a little bit surprised by the corrected text OP posted in her/his article ( http://www.runwes.com/images/learningfrench/image1.png ). Most of the corrections she/he received are not justified at all. Like using the work "crédits" is totally fine in this context. I can't get why they corrected some connectors like "à" or "pour", as the usage of these in the text seem at least as correct…
In fact, the only correct correction among all that red is to replace "gym" by "salle de sport". Not to be confused with "gymnasium", it's similar but not the same thing.
The 4th line is misusing the future tense. Should have been pointed out.