Dr Salvus, hey so I've completed the review. If you have any questions feel free to communicate them to me here or on my talk page. I would suggest looking at other good articles or articles of larger more developed articles to get a hang of what a well developed article should look like and using their structure as a model to develop this article for a later re-nomination. Tayi ArajakateTalk13:23, 29 April 2021 (UTC)[reply]
Before anything else, there are a number of major issues with the article that needs to be looked into. I'm failing this nomination for the time being, primarily due to the lack of comprehensiveness in the article. The assessment table provided above should give a better idea in what areas the article is lacking and in what areas the article fulfills the criteria of a good article. I will list a number of points with more specificity in reference to the issues which prevent the article from fulfilling the good article criteria. Tayi ArajakateTalk12:18, 29 April 2021 (UTC)[reply]
The article needs proofreading and copyediting. There are a number of spelling mistakes, typos, etc in the article, for example "mediaeval ages", "cityuntil", "was confiscated and was assigned".
The section called "Main sights" reads like a travel guide. Most of it could be incorporate into a well developed article as features of the city but not in this form.
There is a bracketed portion in History called "(see Sicilian Expedition)", this should be incorporated a part of a sentence, something like "During the Sicilian Expedition, Gela fought the..."
Comuni-Italiani.it, unclear if this is a government site or an information agregator. If it the latter, it is unlikely to be a reliable source.
gelabeniculturali.it, appears to be a blog.
storiafacile.net, appears to be a blog.
Bethel Bed and Breakfast, hotel reservation site, equivalent to a self published source.
storiain.net, appears to be a blog.
adviceandresearch.blogspot.com (Division Livorno counterattack at 1943 Gela landing), blogspot upload.
I may have missed some, in general one should avoid blogs or travel sites and instead make use of scholarly works such a journals and books or at least newspapers and in some cases government sites. I would recommend looking at the other good articles of cities to get a better idea of what kind of sources should be used. Tayi ArajakateTalk12:48, 29 April 2021 (UTC)[reply]
There is a mention of a "tyrant named Cleandor" in the article. This is likely an NPOV violation, it needs to be stated from who and where he is described as a tyrant and the activities that he indulged him which led him to be described as one.