Wot I Think: The Binding of Isaac Afterbirth †

The new expansion for the marvelous The Binding of Isaac is a mixed bag. Stick your hand in and, fittingly, given the grotesque nature of the game, you might find a pleasant treat, a razor blade or a little cluster of dingleberries. Toxic dingleberries. For the first time since its release, Isaac really is creaking under its own weight and Afterbirth † feels as overstuffed as a trio of turduckens. It's not a pretty sight, but there is plenty of meat wrapped around all those little choking bones.

The Binding of Isaac is one of my favourite games. I sometimes forget how much I enjoy it but every time I go back in, I want to stay for far longer than is healthy. It's a rare game that keeps me up until dawn at this point in my life, but Isaac does it every time I find a reason to return. A new expansion – or megamod – is the best reason of all, and Afterbirth † sucked me straight back into the womb and the horrors beyond, where I found new items, faced new enemies and fought a tediously tricky new boss.

There's a lot here that is tediously tricky. Isaac has always been packed with secrets and unlockables, and the amount of stuff combined with the random layouts of each floor can make it seem haphazard. Play for a few runs though and you begin to realise how much control you actually have. Sometimes you're at the mercy of blind luck and have to make the best of whatever items and disfigurements come your way, but eventually you'll find the means to load the dice and stack the deck in your favour.

Afterbirth † makes the game seem bloated. Even its best ideas don't feel at all necessary, even after a good few hours of play and a couple of completions, and its worst insertions are to be tolerated rather than enjoyed. Prime among the latter are portals, which spawn enemies (and don't look very Isaacy while they're doing it) like something out of Gauntlet. They're overused, making too many rooms a slog, and making the screen too busy. The screen is often cluttered now, and that feels like a shortcut to increased difficulty, as do the enemies with stacks of hitpoints. They're not interesting, in their patterns or behaviours, they're just spongier.

The centre of the game is as delicious as ever, but it's bookended by opening stages that are stodgier than before and a new 'final' boss that For me, Isaac has two distinct styles of play: improvisation and tactical. The former is what all new players become familiar with, struggling through mobs of shit, spiders and flies with nothing but a blood clot and a stream of piss with which to defend themselves. The clot might be toxic shit or a horrid but character-building injury on one run, and that stream of piss might be a stream of electric tears – the point is, you'll make do with whatever the game drops in your path and try your best. And then, directly and more obscurely, the game starts to present ways that you can take a little more control, allowing you to discard and redraw from the deck, reroll the dice, and build the Isaac you need rather than the one inflicted on you.

It's an imperfect process but if you want to unlock everything the game has to offer, you'll need to dig into the tactical side of things, matching characters with the items that work best for them, and combining pickups to bring out the best in them. Afterbirth †, on paper, looked like it was going to focus on additions that would please those kind of players, the ones who've been around since the early days and are looking for a new challenge. Unfortunately, it doesn't appear to have any particular focus, instead throwing a load of mucky stuff at the wall and hoping that some of it sticks.

Plenty does stick. The new items are mostly welcome, with a few, like the Dull Razor, being both a smart spin on old items and allowing clever manipulation of existing mechanics. Additional enemies sometimes mix things up in a way that keeps you on your toes as well, and that's pleasing when you've been around the block a thousand times or more.

The difficulty curve has had something foul and slippery spilled onto it though and from the very first level, it can be almost impossible to find any purchase. One run might find you laden down with keys or coins, dripping with helpful sores and lesions, while the next finds you empty-handed (and empty-headed), and forced to face rooms packed with enemies, portals and Stone Fatties, new variants that neither take or inflict damage, but swarm you and block you into corners. Isaac's difficulty curve has always been more like a cardiogram but Afterbirth † exacerbates every problem, particularly in the early game.

Survive the first couple of floors and you're usually well on your way to a decent run, or at least you have some level of control over your success. But in those early stages, I've felt like I might as well chuck in the towel far too often. I've always loved the fact that Isaac respects my time, even in the first minutes after losing a phenomenal build when taking control of the vanilla character feels like moving from the glorious open road to a jammed suburban roundabout. I can endure the slow beginnings, short as they are, because I'm moving toward something. Afterbirth † sucks away some of that momentum and over the last couple of days, Isaac has wasted more of my time than in the years since it came out.

Too often it's mashing together existing parts of the game and producing either a weak cover version or a clumsy remix. The bosses are the clearest example of that. Even my favourite of the additions, Big Horn, is an interesting fight marred by its length and habit of popping up far too early in a run. The final boss is worse: a personification of the RNG giving you the middle finger and crapping all over your best efforts, Or rolling over and letting you tickle its belly before fading from the screen and from memory. It's unimaginative and naff.

The Sisters Vis are worse still, combining all of the expansion's worst qualities in one fight. Recycled attacks: check. Poor telegraphing of those attacks: check. Absurd hit point count: check check check. Greedier mode takes a similar approach to similar effect, adding insult and injury (fewer coins, tougher enemies!) to Afterbirth's wave-fighting coin-collecting challenge mode, but failing to make it more compelling.

It's a frustrating expansion, though there's every chance patches will address some of these complaints. McMillen has already said that portal percentages and other issues mentioned are on the list for patching. Pick through the shit and you'll find the nuggets of gold, but if I hadn't sucked every last drop out of Afterbirth, I'd rather be playing that than Afterbirth †. As it is, I'm just about won over by the promise of new things, many of which are solid additions, but there's a lot of dreariness to tolerate. I haven't had chance to spend anywhere near as much time with megamod Antibirth but it's immediately more interesting, and free. If the modding tools included with Afterbirth † allow for more of that sort of thing - and mods are now rolled into the base game - that support rather than new official content might be the expansion's greatest legacy.

The Binding of Isaac: Afterbirth † is out now, and is available on Steam.