Games With Gold. Buy the $60 yearly subscription and Microsoft throws in a few titles for free on the first and 15th of each month. So? Are they good? Are they old? Is this stuff anyone would care about?

Polygon is looking back on the year in free games today by picking apart both the dollar value of free games given out by Xbox Live and PlayStation Plus and the critical score of each game on offer. Here is our analysis of Games With Gold, which in 2015 gave out 42 discrete titles for the Xbox One and Xbox 360.

All told, a $60 Xbox Live Gold subscription in 2015 returned $946.53 in games to a subscriber who had both consoles. This monetary figure counts the same title on multiple platforms only once. (For example, a game on both Xbox 360 and Xbox One that costs $20 on each platform counts only $20 toward this total, not $40.) The prices are for the digital version of the game on the Xbox Marketplace as of yesterday.

Getting Started

Counting each version as an individual game, Games With Gold offered 47 games for free on the two consoles in 2015, and they averaged a rating of 76.

Games With Gold presented a number of challenges in writing an apples-to-apples comparison to PlayStation Plus. For example, the offer of Pool Nation FX on Xbox One Games With Gold from April to June. For purposes of Metacritic scoring, we counted this title in all three months. For purposes of value, and among the roster of titles offered, Pool Nation FX is only counted once.

Xbox Live also offered several titles on Xbox 360 in one month that were offered on Xbox One in a later month, as opposed to PlayStation, where multiplatform titles were all offered in the same month. Additionally, in November and December, backward compatibility introduced to Xbox One meant that any free Xbox 360 games in those months were also available for Xbox One subscribers, even though it was literally the same game.

Further complicating the comparison, Xbox saw "special edition" re-releases — games with extra content or features and not simply a remastering or a straight port. We considered these to be a separate title. So CastleStorm and Tomb Raider's "Definitive Editions" thus count separately from their original titles, also offered in this program over the past year.

In totaling the annual value offered by Xbox One, we also counted the same game twice if it was offered in a later month on a different platform. And in the case of the same game offered on the same platform in multiple months, its score was counted and averaged in all of the months it was offered.

Our reasoning behind all of this is that, when assessing the monetary value of a free offer, a discrete title should count only once. Assassin's Creed 4: Black Flag is fundamentally the same on 360 and Xbox One, it's just offered in different months. A person with both platforms does not meaningfully benefit twice from having the game on each platform, except maybe in hard drive management, which is another kettle of fish

When assessing the critical reception of a game, however, the experience and quality can be different from platform to platform. So in averaging critical scores and monthly quality, each platform appearance of a game is treated as an individual game.

This dual standard is in place to prevent multiple copies of a game from inflating the value of the subscription, while also ensuring the entirety of this catalog's critical merit is reflected.

What about PlayStation Plus?

• That analysis is here.

With all that out of the way, let's break down what Xbox Live Games With Gold gave away, month-by-month, how good it is and how much it really costs.

January

Dark Dreams Don't Die (Xbox One)

MX vs. ATV Alive (Xbox 360)

The Witcher 2: Assassins of Kings (Xbox 360)

Average score: 75.6

Total value: $64.97

Skinny: The Witcher, currently going for $29.99 makes this a respectable month in both rating and money.

February

IDARB (Xbox One)

Brothers: A Tale of Two Sons (Xbox 360)

Sniper Elite V2 (Xbox 360)

Average score: 76.6

Total value: $59.97

Skinny: Sniper Elite is not for everyone's taste, but it's not going to lower its price to make friends, either. This was a rare chance to see what that fuss was about without paying.

March

Rayman Legends (Xbox One)

Tomb Raider (Xbox 360)

BioShock Infinite (Xbox 360)

Average score: 90

Total value: $69.97

Skinny: Xbox Live Gold paid for itself in this month.

April

Pool Nation FX (Xbox One)

Child of Light (Xbox One)

Gears of War: Judgment (Xbox 360)

Terraria (Xbox 360)

Assassin's Creed 4: Black Flag (Xbox 360)

Army of Two: The Devil's Cartel (Xbox 360)

Average score: 68.7

Total value: $108.94

Skinny: Three more titles boosted the dollar value but two utter dawgs in Army of Two: The Devil's Cartel and Pool Nation FX dragged down the quality.

May

CastleStorm: Definitive Edition (Xbox One)

Mafia 2 (Xbox 360)

F1 2013 (Xbox 360)

(Pool Nation FX was extended from April)

Average score: 63

Total value: $88.96

Skinny: Even 18 months old, F1 2013 comes in at a huge $39.99 price point to prop up a weak month.

June

Massive Chalice (Xbox One)

Just Cause 2 (Xbox 360)

Thief (Xbox 360)

(Pool Nation FX was extended from May)

Average score: 64.3

Total value: $78.96

Skinny: Gamers and reviewers took a justifiable crap on Thief but it was still a lot higher, in both price and review score, than Pool Nation FX. Three months? What did Xbox Live see in that thing?

July

Assassin's Creed 4: Black Flag (Xbox One)

So Many Me (Xbox One)

Plants vs. Zombies (Xbox 360)

Gears of War 3 (Xbox 360)

Average score: 87

Total value: $79.96

Skinny: Shrugging off Pool Nation FX, Games With Gold shoots back to its second highest month (by average rating) of the year.

August

Metal Gear Solid 5: Ground Zeroes (Xbox One)

How to Survive: Storm Warning Edition (Xbox One)

Metro 2033 (Xbox 360)

Metro: Last Light (Xbox 360)

Average score: 76

Total value: $79.96

Skinny: Four $20 games hovering around 75. That's called par for the course.

September

The Deer God (Xbox One)

Tomb Raider: Definitive Edition (Xbox One)

Battlestations Pacific (Xbox 360)

Crysis 3 (Xbox 360)

Average score: 74.25

Total value: $89.96

Skinny: Again, Tomb Raider: Definitive Edition is a game that by itself almost makes the $60 Xbox Live Gold sub worth it. But who heard of The Deer God before or after this month?

October

Valiant Hearts: The Great War (Xbox One)

The Walking Dead: The Complete First Season (Xbox One, Xbox 360)

Metal Gear Solid: Ground Zeroes (Xbox 360)

Average score: 82.3

Total value: $59.97

Skinny: The Walking Dead's first season was available on both Xbox 360 and Xbox One in this month so it only counted once. Still, it's Xbox's third month with all games rated 80 or better.

November

Pneuma: Breath of Life (Xbox One)

Knight Squad (Xbox One)

Dirt 3 (Xbox One), (Xbox 360)

Dungeon Siege 3 (Xbox One) (Xbox 360)

(Backward compatibility for Xbox 360 Games with Gold titles begins on Xbox One)

Average score: 73

Total value: 79.96

Skinny: Meh. Microsoft was probably more concerned with selling consoles and first-party titles in this month than add-ons here.

December

The Incredible Adventures of Van Helsing (Xbox One)

Thief (Xbox One)

CastleStorm (Xbox 360)

Sacred 3 (Xbox 360)

Operation Flashpoint: Dragon Rising (Xbox 360)

Average score: 70.2

Total value: $84.95

Skinny: Did Square Enix have a deal where it would offer Thief free, but only if there was another game on the list that reviewed worse?

Wrapping it up

Games With Gold is definitely the service for those expecting video games with a lot of name recognition. They just may be a couple years old — or more. The price points are higher, which is entirely up to Xbox and the game's publishers, of course. But so is the rating, which on average is a solid half a point better than the titles offered on PlayStation Plus. That's even with a couple stinkers thrown in, including one that totally overstayed its welcome in Pool Nation FX.

Xbox Live Games With Gold is where one would look for a greatest hits collection rather than anything cutting edge. It had no companion to Rocket League on PlayStation Plus, for example. But then, PlayStation Plus didn't turn in a month like March did for Xbox, which dropped Tomb Raider, Rayman Legends and BioShock Infinite to average 90 critically. Still other months had one or two big name offerings weighed down by brand-X misfires.

Xbox Live Games With Gold is more like a solid department store showcasing name-brand fashion rather than PlayStation's edgier boutique, which will go to the trouble of finding new looks at the risk of a client not caring for them. Both services offered legitimate value in 2015, with Games With Gold making the most traditional and stable appeal to gamers.

By the numbers

Average score: 76

Average price:$20.37

Total value: $946.53

Platform Averages

Xbox 360: 78.5 Metacritic average, $21.60 per title.

Xbox One: 72.77 Metacritic, $18.08.

Highest rated Xbox 360 game: BioShock Infinite (93)

Highest rated Xbox One game: Rayman Legends (91)

Highest price Xbox 360 game: F1 2013 ($39.99)

Highest price Xbox One games: Assassin's Creed 4: Black Flag. Tomb Raider: Definitive Edition and Thief ($29.99)

Lowest rated Xbox 360 game: Sacred 3 (51)

Lowest rated Xbox One game: Pool Nation FX (30)

Lowest price Xbox 360 game: CastleStorm and Operation Flashpoint: Dragon Rising ($9.99)

Lowest price Xbox One game: Operation Flashpoint: Dragon Rising ($9.99)

Metacritic ranges

90 and up: 3 titles

80 to 89: 18

70 to 79: 19

60 to 69: 5

59 and below: 5

Price ranges

$25 and up: 8 titles

$20 to $24.99: 5

$15 to $19.99: 21

$10 to $14.99: 13

$5 to $9.99: 3

$4.99 and under: 0