HD collections and other game compilations aren't games. They're bundles of previously released games that already have their own listings on here. For instance, God of War 1 and 2, which God of War collection is, already have their own entries on here.

Same concept for remasters, which are graphically upgraded ports of games. For instance, there's no reason to have both God of War 3 and God of War Remastered listed, since in principal, they're the exact same game. Same for The Last of Us and the Last of Us Remastered.

Most of the collections you're referring to are compilations here that include the original entries under the umbrella of the collection.
As for remasters, etc: this is a collector site, and variations of versions matter to a lot of collectors. That's why there are separate entries for different versions of the same game. Similar to all the different versions of an album that you'll find on Discogs because version matters.

Yep, as @Drymonema said, the collection side of things is a big driver for having separate entries for remasters and compilations. Things get even more detailed for the items supported on the Browse by Platform page since you can get into different variant type releases, such as Greatest Hits versions and whatnot, which is important from a collector's perspective. Of course, that can sometimes lead to separate entries altogether when a game is altered, such as The Lost World: Jurassic Park - Special Edition, but luckily that's not too common

The beauty of this site is that you can build your 'collection' however you wish to do so. This site offers a lot of flexibility and that's pretty great IMO.

If the HD Remasters, Compilations and the HD Collections don't make sense, then simply ignore and add the games that make sense to you.

I think a fair share of the community utilizes these things though when trying to catalog their collections or just want to keep all the various iterations that they own organized to easily lookup and see what they own.

Makes sense, but I'm concerned about the time it takes to beat a particular game. If a game has multiple entries, is the completion time for each entry averaged to give the most accurate time?

Also, why not just have one entry per game and let users select which version/edition of the game they have from a drop menu?

@sjwsruineverything all the individual completions are added for compilations. For example if you beat all the games in Sonic Mega Collection all the completions are added. Having multiple entries also allows people with multiple copies of the same game but different variants to account for them.

@sjwsruineverything all the individual completions are added for compilations. For example if you beat all the games in Sonic Mega Collection all the completions are added. Having multiple entries also allows people with multiple copies of the same game but different variants to account for them.

What?

I hope this site is better than Howlongtobeat

The site does not average or compile times across different games in any capacity. Currently, each entry is a unique, standalone item with its own statistics. I do agree that in some instances, there is value to be had by compiling data and this is something I've considered implementing for a while. For example, Beyond Good and Evil and Beyond Good and Evil HD are more or less the exact same game. The latter has a higher resolution and trophies / achievements, but otherwise they're the same (at least, as far as I could tell when I played them.) So in that case, it certainly makes sense that they could be "loosely" connected and optionally have their completion time statistics merged on their details pages: Original and HD.

In order to support something like this, the system would need a way to link games together in this sort of relationship (i.e. source --> remaster.) But it's not just remasters, there are a few more (at least) that should be considered:

• Re-release - This would cover things like when a game isn't really remastered, but just sort of re-released as a slightly different package, likely with more content. One example of this would be Resident Evil: Director's Cut, which is basically the original game, but with an additional "arranged" mode. This had its own re-release by way of Resident Evil: Director's Cut - Dual Shock Edition, so it can actually go deeper than one layer.
• Remake - This would cover when a game is completely remade from the ground up. The recently released SpongeBob SquarePants: Battle For Bikini Bottom Rehydrated is a good example of this. As far as I know, this game is very similar to the original, but you also have things like the Resident Evil remake for GameCube that are significantly different. While it's debatable whether these should allow you to merge completion times (because, again, they can be drastically different), but it would be nice to have the system know they're connected in some way.
• Reboot - This is when a game / franchise is just completely rebooted and the developer / publisher is starting over. A good example here would be Tomb Raider (2013). These can be tricky to identify sometimes and, in my opinion, aren't nearly as important / useful to know as the other types. And they certainly wouldn't be eligible for merging completion times since they're totally different games.

Ultimately, the reason this hasn't been implemented yet is that it simply takes time to build things and this is such a low-priority feature. The percentage of games that would fall under any of these categories is extremely small compared to the overall size of our game database. Furthermore, we are a very small site / community and most games don't even have a completion time, so there's often nothing to merge. So yes, it would be nice to see times merged in certain instances, but I have yet to justify the development time to build such a feature over other items. That doesn't mean it won't happen, just that it's not on my radar yet (but it's nestled on my task list somewhere )

But development is only the first part of implementing something like this. Once we have the hooks in place, now we have to enter all of the data. That means sifting through and finding all of the things that need to be connected in the roughly 47,000 items in the database as of this moment and then maintaining it over time.

tldr; It would be nice have the option of merging completion times in some instances, but probably a ways off from happening because...time.

If your sole concern is completion time estimations averaged from a large userbase, you're definitely better off using a site like howlongtobeat as they are a much more specialized and narrow-focus site with a larger dataset for that kind of info. However, if you're looking mainly to track your own completion times (via playthroughs) while also being able to catalogue your games collection with lots of detail, then this site offers a far greater breadth of features. Poke around and get a feel for things and see if it meets your needs.