Our two and a half year old daughter has had a strange fear of slides and swings for some time (maybe half a year or more). She doesn't dare to slide alone, only if someone holds her hand, except for very small slides. And even very slow swinging is too wild for her and after few seconds she has enough. Compared to other children, she is a real coward and hardly dares to do anything. But she is very skillful e.g. at climbing.
In the garden she has a great playhouse with swings and a slide and had already done it all by herself and loved it and also swung wildly when she was younger, but not anymore. In winter, of course, we did this less often, but were still often on playgrounds and the like.
About our daughter: She is generally very reserved and cautious, rather introverted and thoughtful, but makes a very intelligent impression on us, among other things because she is already very developed linguistically. If you want to know anything else, please just ask.