Zotero Web Translator for Steam Games (store.steampowered.com). No fancy checks for pages, so only use on app pages.

SteamSoftware.js

{
	"translatorID": "92c1c200-6cca-4dd0-8d61-573a50a60f16",
	"label": "Steam Software",
	"creator": "Ste",
	"target": "store\\.steampowered\\.com\\/app",
	"minVersion": "5.0",
	"maxVersion": "",
	"priority": 100,
	"inRepository": true,
	"translatorType": 4,
	"browserSupport": "gcsibv",
	"lastUpdated": "2024-02-01 21:55:08"
}

function detectWeb(doc, url) {
	return "computerProgram"
}

function doWeb(doc, url) {
	// Extracting title
	let title = ZU.xpathText(doc, '//div[@id="appHubAppName" and @class="apphub_AppName"]')
	
	// Extracting date, developer, and publisher
	let date = ZU.xpathText(doc, '//div[@class="release_date"]/div[@class="date"]')
	let developers = ZU.xpathText(doc, '(//div[@class="dev_row"])[1]//div[@class="summary column"]/a')
	let publisher = ZU.xpathText(doc, '(//div[@class="dev_row"])[2]//div[@class="summary column"]/a')

	// Create a new Zotero item
	let gameItem = new Zotero.Item("computerProgram")

	// Set metadata fields
	gameItem.title = title
	gameItem.date = date
	developers.split(",").forEach((developer) => {
		gameItem.creators.push({
			"lastName" : developer.trim(),
			"creatorType": "author",
			// author as a single field since most developers are like institution names
			"fieldMode": 1, 
		})
	})
	gameItem.company = publisher

	// Extract web Embedded Metadata
	let translator = Zotero.loadTranslator("web")
	translator.setTranslator("951c027d-74ac-47d4-a107-9c3069ab7b48")
	translator.setDocument(doc)
	translator.setHandler('itemDone', function (obj, webItem) {
		// merge, overwriting the web data with game data
		let merged = {...webItem, ...gameItem}

		// Save the item to Zotero
		merged.complete()
	})
	translator.translate()

}
/** BEGIN TEST CASES **/
var testCases = []
/** END TEST CASES **/

This is just a quick importer, not super safe with page types etc., that's why I didn't pr it to https://github.com/zotero/translators yet.

Install:

1. Download that JavaScript file
2. Find your Zotero user data folder (Search for "Zotero")
3. Drop the file into the translators folder
4. Right click the browser extension -> options
5. Go to "advanced"
6. Press Update Translators
7. Collect your first clean Steam citation