The Legend of Zelda (NES VC on 3DS):

I finally completed it.
Similarities between the first Legend of Zelda and The Binding of Isaac are obvious -- UI is almost identical:

BoI also takes some of the ideas of LoZ and builds new systems on top of it. LoZ has some special properties on hearts number: like sword beam is only active if you health is full. BoI goes one step further and doors that can only open if you have full health OR just one heart or a curse that boosts damage if you have half a heart (i.e. one hit away from dying) and so on.
It was kinda cool to play original game and retroactively recognize things that Binding of Isaac took, like one of the first bosses you encounter in Binding is actually one of the sub-bosses in the last dungeon of Zelda, and i knew of that just a week ago, because i obviously beat it only now. Spiders' (annoying) movement patterns are copied wholesale from LoZ. Some of the enemies can only be hurt from the back or the sides just like Zelda knights.
But this E3 i saw that this creative borrowing of ideas can go both ways because new Zelda game introduced yellow hearts which are the same as blue spirit hearts of The Binding of Isaac.
Okay so the game itself.
I've been trying to beat the game for years now. When i played on my original 3DS a few years back i managed to get to 8th dungeon -- and all by myself, without looking up anything which was and still is my big problem with all Zelda games (unintuitive puzzles gating my progression). I'd rather be left alone and look and wander and bomb random things rather than be stumped by a puzzle the logic of which i don't understand and get mad when i look up the solution. But then i lost 3DS and with it -- the game.
Obsessively playing Binding of Isaac for the last months and last E3 sale pushed me to buy it again and complete it.
I also had to look up where the last dungeon and this time i wasn't even angry when i saw the solution because i completely misunderstood "spectacle" in "spectacle rock" hint as a theater play and there was absolutely no way i would have gotten it by myself because i would have gone looking for things that look like theater stages instead of glasses. Still, 8 dungeons i found by myself -- that's the best ratio of any Zelda game i played so far.
Mages in the last dungeons were very annoying especially on that one room on the screenshot above where you have no space to move and dodge. I gotta admit i was spamming save-states on these rooms just to get through it.
The game unlocked second quest and i played it for some time and beaten two dungeons by inertia. 2nd dungeon placed in secret shop location was pretty cool -- i was surprised when i entered it wanting to buy a shield on cheap and discovered that they moved around all dungeons. But i don't think i will be coming back to it.
Still, cool game that inspired even better games. I kinda wished Zelda after that didn't shift the focus from action to puzzles that much, but it seems like new Zelda games is coming back to roots and is doing exactly that so i am excited.
Binding Of Isaac: Wrath of The Lamb: Eternal Edition: Not Rebirth, nor Afterbirth (Steam):

With 490+ hours, it is my second played game after TF2.
Though a good 100 of those hours is just me leaving this game to run idly on my work PC. I arrive to work at around 8:30 so i use that half an hour to start a run and if it's worth keeping i keep game's window open in the background while i do my work until lunch break. Few times i kept especially promising runs on the pause like that for the night to resume them on the next morning. And one time i kept the run on pause from friday to monday.
Still, what made me play this seemingly simple game for 400 hours, collecting all 99 achievements?
The Binding of Isaac morphed from rather simple gamejam Zelda tribute into mechanical monster, bottomless well of depth with numerous versions/editions, 10+ endings, hundreds of unlockable items and secrets, tens of trinkets, a set of tarots cards, dozen playable characters each with their own strategies and item synergies and numerous ways to abuse the engine.

On the surface it's all rather simplistic and it
WAS that way back in 2008 when i bought this game initially. I started it and 45 minutes in, beat Mom. "Okay that was fun, i guess". 7 years later i randomly started playing it again, and oh man have they added some STUFF since.

When i came back i started to see how the game really works, first i realized that keys are the most important resource because they give you access to treasure room on each floor which are guaranteed to have an upgrade of sorts. Then i discovered wikis on the game and
Platinum God site and oh man. It was like a abyss opening and day by day by day i was figuring out how to break the game further while it kept throwing new and new challenges at me.
After you beat Mom ten times you unlock new level with new boss, then beat it dozen times and you have two new chapters that require additional conditions to even enter, then yet another chapter beyond that and then finally the finale, the true real no-kidding-this-time ending. You need to beat penultimate chapter five times to unlock the item that allows to enter the final chapter.
And with each "final" boss game changes dramatically -- you unlock more beneficial power-ups, entire systems become available to you, metagame evolves into the sprawling mess of systems and synergies. After a certain number of "Mom kills" game reaches milestone where it activates new set harder enemies and bosses. And alternate characters! Metagame is vastly different for most of them which provides a satisfying variety:
- Magdalene simply tanks damage with her big health pool. But you can risk big and trade heart containers to devil in exchange for various devil items. But she also has crippling low speed so you need to be on it with your dodging constantly or find speed-up upgrades ASAP.
- Samson is an inverse of Maggy because he only has 1 heart but to make up for it he has an innate ability where your damage gets a temporary boost each time you kill an enemy. This trivializes bosses that spawn smaller enemies because you can get 4x damage by killing mooks first and then go ham on a boss itself.
- Judas has a very good power-up (Book of Belial) unlocked from the start which boosts your damage. Book of Belial also has a hidden synergy which increases the chance of Devil room appearing even if you take damage on the level.
- Cain has hidden Luck stat boosted up which generally gives you better unlocks and especially helps in arcade room where you can grind for pick ups.
- Blue Baby (???) doesn't have permanent heart containers which means if you lose a heart -- that's it. Game changes dramatically with blue baby because shops and tinted rocks that you can blow up for blue hearts become your main source for health. On the other hand, Blue Baby is probably has the most beneficial Deal with the Devil mechanic which arguably allows him to become overpowered glass cannon faster than any other character.
- Eve is probably one of the most ingeniously designed characters because you have to harm yourself on purpose to stay with only half of red heart to achieve cursed state where you have your damage boosted. This mechanic also synergizes with blue hearts system because you can use them as your your damage shield of sorts while keeping your red heart at .5. It is even beneficial to destroy all your red hearts completely and go completely broke with just blue hearts (like Blue Baby) because you can then stay cursed forever and not have to dodge red hearts in fear that they will replenish your HP and lift the curse.
"Harming yourself to become stronger" and sacrifice in general is a major theme of the game -- how far are you willing to go to reach the final boss? How much are you willing to sacrifice -- your health, your time? You arrive at final boss as some insane looking overpowered abomination -- but at what cost?

And finally -- Isaac himself who is at the beginning has all stats on average but sometime into the game he changes and gains potentially the most overpowered item in the game -- The Dice.
The Dice exposes yet another deep and abusable mechanic of BoI --
item pools. The Dice allows you to "reroll" items that you RNG gives you in treasure, secret, angel and devil rooms. So if you don't like what game has given you on a pedestal here? Use the dice to change it into something else that you haven't seen before. For the first level you have a chance to reroll item in treasure room twice giving you a chance to choose and pick between three potential items.
D20 item that you can get later gives you even more control over item pool because now you don't have to have item on a pedestal to reroll -- you can reroll randoms pickups that are just lying on the floor. Game gives you even more ways how to break the game with D20 than with D6 with synergies.
Eternal Edition:
Eternal edition is an official update to the game that adds hard mode. Apparently it is controversial because most players think it is
way too hard. I think they're weird because as a reward for having to deal with very hard tanky regular enemies and bosses Eternal edition also gives you "eternal" white hearts like candies, which allows you to get more permanent health containers. This changes the balance between characters significantly. Characters who have low health as a handicap are not crippled by it so much because you can get more health if you're good at the game (and then trade all that health in to devil for deals anyway).
Reibrth:
This game is original Flash-based release, in the years than i haven't played it, creators have released revamped game on new engine with even more content and systems and even ported it to consoles (Wii U included).
I didn't wanted to buy it, because i didn't wanted to redo everything from the start, after spending so much time with original game. Still looking at some of the videos here and there it seems like Rebirth+Afterbirth is an even bigger monster. I WILL buy and play and complete that game too -- but some time later, now i need to rest from Isaac for a while.
TLDR:
Now imagine me playing this game till 4am and hearing THIS for the first time X-(