The game bundle SEGA Mega Drive & Genesis Classics (https://www.igdb.com/games/sega-mega-drive-and-genesis-classics) contains a large amount of games on the webpage, but in the API only one game is returned, sonic:

'fieldsname, url, bundles; where bundles = (80185); limit 50;' https://api-v3.igdb.com/games
[
{
id: 3192,
bundles: [
4157,
7189,
20502,
20621,
22297,
46204,
80185,
86067,
96393,
99953
],
name: Sonic the Hedgehog,
url: https://www.igdb.com/games/sonic-the-hedgehog
}
]

If you pick one of the games listed on the web page as in that bundle that is missing from the API, for example Gain Ground, the web page for Gain Ground says it is available in the following bundles:

Sonic's Ultimate Genesis Collection, Sega Genesis Collection, SEGA Mega Drive & Genesis Classics, SEGA AGES Sonic The Hedgehog

But the API responds that the game appears in the following bundles:

'fields name, url, bundles.name, bundles.url; where name = "Gain Ground";' https://api-v3.igdb.com/games
[
{
id: 3129,
bundles: [
{
id: 7189,
name: Sonic\u0027s Ultimate Genesis Collection,
url: https://www.igdb.com/games/sonic-s-ultimate-genesis-collection
},
{
id: 20621,
name: Sega Genesis Collection,
url: https://www.igdb.com/games/sega-genesis-collection
},
{
id: 91043,
name: Duplicate SEGA Genesis Classics,
url: https://www.igdb.com/games/duplicate-sega-genesis-classics
},
{
id: 96393,
name: SEGA AGES Sonic The Hedgehog,
url: https://www.igdb.com/games/sega-ages-sonic-the-hedgehog
}
],
name: Gain Ground,
url: https://www.igdb.com/games/gain-ground
}
]

As some reviews age, some sites can go out of business or just shut down. However there doesn't appear to be an automatic way the database removes or reports broken links or updates scores as they go away. Additionally, some of these will push scores averages down if they continue to inaccurately are placed as Review Scores, yet hold broken links.

Steel Battalion
https://www.igdb.com/games/steel-battalion
- 404 Review Links (Gaming Trend)

Fatal Frame II: Crimson Butterfly
https://www.igdb.com/games/fatal-frame-ii-crimson-butterfly
- Inaccurate count of 3 reviews on Game Page, but 2 reviews listed on Critic Reviews breakdown page.

Disgaea 2 Dark Hero Days
https://www.igdb.com/games/disgaea-2-dark-hero-days
- Worth Playing: Review scores 8/10, but is listed as an Unscored Review
- 404 Links for Gaming Trends, Digital Chumps.

Jak & Daxter Collection
https://www.igdb.com/games/jak-and-daxter-collection
- 4 active links rate at 85-75, but 2 broken links rate 70-66. (GameZone/Digital Chumps)

My Search query to IGDB API is failing with status code 400 if the search text contains a back slash \ in it:
I am using below syntax:
const { q } = req.query
let fields = name, collection
apicalypse(requestOptions)
.fields(fields)
.limit(50)
.search(q)
.request('/games')
.then(response => returnResponse(response, req, res))
.catch(err => returnError(err, req, res))

requestOptions are like this:
const apiPath = 'https://api-v3.igdb.com'
const defaultHeaders = {
'Accept': "application/json",
"user-key": apiKey
}
// Apicalypse Request Options
const requestOptions = {
queryMethod: 'body',
method: 'post', // The default is get
baseURL: apiPath,
headers: defaultHeaders,
responseType: 'json',
timeout: 10000
}
q is \ if I send \ from front-end & abc \ xyz in case of abc \ xyz.

The current popularity value for a game doesn't make any sense.
Please see below examples showing the popularity value with the hypes, and number of user ratings.

"id": 115278,
"hypes": 1,
"name": "Rune Factory 4 Special",
"popularity": 2090.622837928576

"id": 120268,
"name": "Zombie Driver: Immortal Edition",
"popularity": 1431.973719413489

As you can see, the top 2 games by popularity both have 0 user ratings. How can these be the most popular games on IGDB?

The docs say 'The popularity number is calculated using usage statistics of game pages at https://www.igdb.com' which can't possibly be true if these games are at the top.