The RPS Advent Calendar, Dec 23rd: The Binding of Isaac: Afterbirth

What is the best expansion pack of 2015? The RPS Advent Calendar highlights our favourite games from throughout the year, and behind today's door is...

The Binding of Isaac: Afterbirth!

Adam: The original release of The Binding of Isaac was one of the first games I reviewed here at RPS. Here's wot I said, in brief:

For the meagre sum of £3.59 there’s an embarrassing amount of entertainment here. In many ways, it’s a small game. There’s never more than one-screen in play for one thing but every screen has something to offer, whether an ecstatic discovery or a terrible way to die. That’s fundamentally all I ask from a game – fill my screen with something interactive and interesting. It’s a very rare moment when Isaac isn’t doing that. As I was playing, I kept thinking how unlikely it was that this thing exists, in all its deliberate depravity and simple pleasures. I’m extremely glad that it does.

I didn't expect to be writing about a gargantuan remake four years down the line. Everything that I said back then is still true, the single screen rooms aside, and every element that I loved has been expanded. There are more things to collect, more secrets to discover, more monstrosities to kill and more mutations for Isaac to graft onto his body.

Even though I don't like to disagree with myself, describing Isaac as "a small game", in any way, seems a bit daft. I'll never complete it - no matter how many times I beat the final boss(es) and no matter how much time I spend unlocking new items, after four years I still feel like I'm scratching the surface. And the additions since that original release, culminating in Afterbirth, have increased the number of surface layers as well as digging deeper into the basement (and what lies beneath the basement).

Isaac is a modern classic. There are many games that I love and among those there are a few that I reckon deserve to take a place in my list of desert island discs. If I had ten games to play for the rest of my life, or ten games to plant in a capsule for future generations to learn from and to enjoy, The Binding of Isaac would be one of them. Invisible, Inc. as well, on this particular Calendar. Both are games that I knew I'd love within minutes of loading them up for the first time, and I fully expect both to be just as enjoyable ten or twenty years down the line.

It may have a Greed mode in its latest incarnation, but The Binding of Isaac is an extremely generous game. It won't waste your time, it won't punish your efforts and it will consistently reward you simply for spending time in its company. I adore it.

Alice: New items are fairly typical expansion fare, but they come as bigger swords or guns with fancier art and higher numbers. You do the same thing, only now it's fancier. If you're lucky, you'll get a new class with a few new tricks. In Isaac, where every run is different and one item can massively change how you play, additions are a huge deal.

Gosh oh golly, it adds so much. A game I've played for over 200 hours feels minty fresh. I still don't even know what half the new items do, and find runs taking strange and interesting new directions I only figure out once I'm done. Even the new room shapes can make or break runs, with the narrow ones especially trashing runs that might've been a breeze in vanilla Rebirth. And new characters. New bosses. New alternate floors. New transformations.

My old strategies, reliable techniques and builds, become obsolete and suddenly I find myself doing the unthinkable. I pick up the awful Experimental Treatment, every time, in the hope that it'll get me the damage-boosting Spun transformation. I'm even warier of anything that might give me exploding shots - death in these narrow rooms. I'm feeding sacrifice rooms to fight angel statues and get key pieces. Yeah, sure, I'll even take ranges stat upgrades for weird synergies and chances for other transformations. It's the Isaac I know and love, only I barely know it anymore. I'm awful again, and it's great.

The new Greed Mode is pretty fun too, offering 20-minute arcadey runs where you get to fight a load of monsters and create overpowered builds. It skips a lot of the long-term planning and inquisitive bits, but I find myself weeping through a quick round most lunch breaks.

And then Daily Runs! The... Daily Runs I haven't done nearly enough of. I'm worried, see. If I start competing, as bad as Isaac as I am, it'll only end badly. I know I'd ruin some of Afterbirth's mystery by researching around new things to maximise scores. But I adore that they are there and, one day...

Isaac is a Scrabble bag. Shake it, take out a few letters, and see what you can spell. Before you'd come up with some pretty cool words. Now it's spitting out letters I've never even seen, creating words I barely understand - some written in blood.

Go here for more of our picks for the best PC games of 2015.