Many separate indie devs have come to the same solution and attempted building a platform for game distribution, even before Steam and GOG were a thing, with various degrees of success. The realities of creating and maintaining such a platform typically diverge quite a bit from those of gamdev, and aren't particularly "fun" to manage...
I've been studying game distribution platforms & bundles for quite a while and have a few opinions on the matter to share. In my experience, the value of Bundles, Steam and other distribution platforms is primarily not in its unification of game distribution and/or uniform platform compatibility. Rather, their primary usefulness is in aggregation of games and content for the purpose of advertisement and discovery. The same holds true for Kickstarter and other crowd source platforms: Their monetary incentive is secondary to the benefit of promoting your game to the eyeballs the bundle/funding-platform/online store has already attracted. See also: Ye 'ol disc on a retail shelf bearing a title such as, "200 shareware games only $4.99"
Community / achievements / etc. features of distribution platforms are all tangential to game discovery. Note that you can easily talk about games and even gift games on Steam -- This promotes discovery. There's a competitive and social angle to scoring which can reinforce a community, this also reinforces other methods of discovery such as word of mouth and "Let's Play" advertising. The Humble Indie Bundle incorporates charity donations and leverages positive social signaling -- people like to point out how much they've helped some charity (meanwhile advertising your game). Like most devs, I find marketing to be quite a soul sucking affair, but that's the nature of the beast.
At this time I'm unprepared to participate in an incubator bundle. However, I can propose an alternative that anyone can participate in even if the developer can't comply with "open platform" restrictions:
If you are making a roguelike (or any game) then you should make a Press Kit. A typical press kit consists of game logos, gameplay screenshots, your catch phrase, an "elevator pitch" (short description of the game), a primary bullet list of features / mechanics (what makes your game worth playing), what platforms are supported, a link to get the game at, and etc. information that would be useful for creation of an article about your game by a game journalist (assuming they exist in this reality). The purpose of the press kit is to make it easy for others promote your roguelike.
Next, post a link to your presskit in a thread dedicated to the promotion of roguelike devs here. Maybe even try sending the kits to game "journalists" and "Let's Players" (along with a copy of the game). Don't ignore the lesser known outlets since they're usually hungry for unique or niche content... but I digress.
Before releasing your roguelike use your discretion to select a few roguelikes from among the other devs' games you appreciate, and promote them in-game by using content from their press kits on a "you might also like" screen, menu item, etc. Think of it like having a separate "credits" screen that promotes other roguelikes you like. The promoted games should optimally be in a playable state and of a sufficient quality or at least in the same vein of the game you're releasing. Try to include links to the other games if possible.
In this way roguelike devs can help promote each other as a dev community while aiding players in discovery of more roguelike games.
I think that an Incubator Bundle could utilize a similar method of cross-game discovery in lieu of or in addition to bundling. You can opt to employ Incubator bundle-branding and quality standards. Meanwhile, those not bundling could promote the Incubator bundle as well as other roguelike devs not in the bundle. My point is to make it easy to do so.
It's a rare thing to help your competitors compete with you, but it seemed to work for us sharware game devs back in the BBS days, and I think the strategy might still be useful today. This wheel has been reinvented many times. Remember Webrings? See also: Amazon's, "people who bought this also bought these", Pandora's music genome project, Netflix, and etc. recommendation engines.
TL;DR: Make & post your press kits, get recommended by other helpful roguelike devs / players, with or without being officially incubated. "A rising tide lifts all boats."
