Some of my favorite childhood platformers are free on Epic for today only, and they've all been updated for better crossplay with Steam owners

Another day, another freebie. There's been a new free game on the Epic Games Store each day since December 18 for the holidays, and today's deal is a four-in-one: the Trine Classic Collection. Not only that, but each game in the collection has been updated so a cross-platform co-op game between a Steam user and an Epic Games Store user is a little less finicky.

Now, when you boot up Trine 1 through 4 on Steam, you'll be prompted to optionally link your Steam and Epic accounts for cross-platform friend invites and achievement progress. The series' headlining feature is its three-player co-op, so this should make playing with anyone who just got the games due to this promotion easier.

If you haven't played Trine, it's a The Lost Vikings-style puzzle platformer with three characters: a bumbling but burly knight, a thief with grappling hooks and a bow, and a wizard who can generate cubes and platformers. In solo play, you can only control one character at a time, but in multiplayer, all three characters are on screen at once. It gets chaotic quickly, but that's the fun bit; the puzzles are good, but rarely major head scratchers.

They were decently popular on Steam when they first hit the scene, and while they aren't masterpieces, they are unfailingly lighthearted, breezy, and fun. The Trine series is the workhorse of the puzzle platformer: there's a new one out every few years and the quality has remained admirably consistent (even considering the 3D black sheep, Trine 3). This bundle doesn't include the latest entry, Trine 5, but there's around two dozen hours of puzzling packed into the first four entries.

Every mention of Trine brings up some warm and fuzzy feelings for me, as it was one of the earlier non-Valve games I played on Steam back in the day. It helped enamor me with the platformer as a young'un and, in part, set me on this path where I squawk about videogames for a living, so I'll always sing its praises for that.

Trine Classic Collection is available for free until December 31 on the Epic Games Store.