Hell is empty and all the demons are here. By here, I mean this train, teaming up with monsters and battling angels across the frozen wasteland that was once their home, until you reach the heart of Hell and reignite it with the flames of the final Pyre. Surprisingly, the game underlying this wild idea is a deck builder very similar to "Slay the Spire," and had I not seen the creators of both talking amicably on the live stream, I might have been a bit skeptical.

"Spire Slayer" had a relic that changed the nature of the run, while "Monster Train" has an artifact with essentially the same ability (the infamous "Snecco's Eye" that randomizes spell costs returns as a "volatile gauge"). "Slay the Spire" has an "ascension" had an unlockable difficulty called "Covenant," while in "Monster Train" it is called "Covenant. Nevertheless, the lack of originality did not bother me. It feels like you are playing a sequel based on ideas from the previous game.

There are many ways in which Monster Train is different from the others. Instead of choosing a hero with his own deck, you choose two monster clans and combine their decks like the colors in Magic: The Gathering. (Some are weird, like the waxy undead Melting Remnant, while others are a bit more mundane, like the plant-themed Awoken.) Each battle takes place on the train's four levels, with three platforms summoning monsters and a pire that must be defended at the top. Swarms of angels enter from the first floor, and those that are not defeated march down the first floor.

Like any deckbuilder, the point of the monster train is to discover combos. My one success with the Hellhorn clan relied on a cheap imp that gave 15 points of armor behind the summoned one. I upgraded it with endless properties to allow it to be summoned multiple times, and departed with a card that allowed me to sacrifice an imp for one point of mana. The imp was repeatedly summoned and exploded behind a champion that was upgraded with the Slay ability. By the end of each round, his armor and attack power were both bellowing, and he was dealing several hundred points of damage each turn.

Finding such combos in a deck builder makes you feel like you're cheating, like you've secretly broken the game. It's a delightful feeling. In Monster Train, you quickly reach a boss with hundreds of hit points and powerful debuffs and realize you haven't cheated the game at all. You did the bare minimum to play competently.

In between battles, the tracks diverge, and each path has several highlights. One path upgrades a spell, restores a cremation, and purges two cards from the deck. The other upgrades units, earns free money, and duplicates cards. The duplicated cards keep their upgrades and you get an obscene combo.

More than any other deckbuilder, Monster Train recommends a lean deck with clutter removed at the start. The trick to play is to plan for the combo from the beginning and build toward it with the appropriate upgrades, rather than discovering the combo along the way and adapting to it. You will be told in advance what the final boss variation will be so you can modify your plan.

This can make the randomness even more frustrating. Each clan's champion (its central zero-cost hero card) has three upgrade paths, but only two of them are offered in a single play. Any run in which the Hellhorn champion is not offered the slay ability from the start is a run I should abandon.

Returning to "slaying the steeple," as you knew, that rhythm of stumbling upon a powerful combo by accident is more uplifting when it works and more nerve-wracking when it is narrowed down to a line. Monster Train is a low dose of the same hit, but suffers from the same itch after a few hours and the first couple of covenants, and is easy to recommend to the "Slay the Spire" faithful.