I touched on this release when EGG put out the MSX2 original a few weeks back, but lemme run it down once more: after the arcade version and subsequent home ports blew up, Compile opted to touch up the existing FCDS game for a cartridge release rather than produce a new, authentic port of the arcade game, but with a few alterations to make it play more like the version people actually wanted: you can raise and/or practically eliminate the garbage cap; 1P & 2P now receive identical drops; there's a plain numerical display for incoming garbage, etc. It still doesn't look anything like the arcade version or offer anything by way of character elements, but you could at least play it with a friend and experience something close to what you'd find in arcades or other consoles, so that ain't nothin'.
@EpsilDelta left a comment on your post
Do you have any opinions on best version on Project EGG? I'm familiar with arcade and console releases.
Either way, giving access to these games, even possibly "interior", versions is amazing and I hope they can keep driving interest towards Compile's back catalogue.
As far as I know, EGG's run of Puyo reissues isn't going to extend past select pasocom ports of AC Puyo Puyo, so the PC98 version that went up last year might be as good as it gets.
I should restate that me keeping tabs on what's happening with Project EGG shouldn't necessarily be read as an endorsement of the service—I do think EGG lead Suzuki's intentions are sound and that they're doing their best to curate and preserve the history of Japanese computer games within their means, but having to pay a monthly sub just to be permitted to buy individual games with a wrapper straight out of 2007 ain't it, and I hope the success of EGG Console gives them the ability and/or desire to step things up.