I had some questions...
1. What classes are included with the initial rules?
Divine: Cleric, druid
Warrior: fighter, berserker, paladin, ranger
Rogue: assassin, thief, bard, monk
Magic User: Wizard, sorcerer
2. What Ancestry's are included?
the basics: dwarves, elves, halflings, gnomes (I know, I know), and humans. But there are also rules for playing monstrous ancestries (orcs, goblins, etc)
3. Do ancestrys work more like BX/BECMI, AD&D, 3e, 5e, Pathfinder, or something else?
More like AD&D, except they don't give stat bonuses (or penalties) and only give a few traits. Stat bonuses are based on class choice, so fighters would allow you to increase +1 to either STR, DEX, or CON. Heritages now give you some of the classic racial traits. For example, if you're a human who grew up in an elven city your whole life, you could choose the fey heritage and gain resistance to sleep and charm. There are many heritages, and you choose two upon creation.
4. Do Warrior's advance in combat ability more like AD&D 2e (+1 to hit every level), 4e (everyone advances at the same rate, with 4e's rate being +1 every 2 levels), or 5e (bounded accuracy, much lower bonuses, everyone advances at the same rate of +1 every 4 levels). How does it relate to other characters combat ability?
Each class group advances at a different rate. Eg., divine characters get a +1 to attack rolls every other level, while warriors get a +1 bonus every level. It's not dictated bounded accuracy like 5e, but closer to AD&D. One of the goals was to be easily convertible to AD&D adventures. So not the numbers bloat we saw in 3e either.
5. How does multiclassing work? More like TSR D&D, 3e/3.5 D&D, 4e/PF2e, or 5e?
Closer to AD&D. Choose your other class, and split XP between them. While every class uses the same XP level chart, you could end up with a fighter 5/thief 3 depending on when you chose to multi-class.
6. How is combat going to work? Is it more like Castles and Crusades, 3e, 4e, or 5e?
More like 3e, when they went to ascending AC. You make your attack roll, add bonuses, and see if you beat their AC. Initiative initially is like B/X, where you roll team initiative, but there is an option for individual initiative as well if you prefer.
Edit: 7. One Last Question, though perhaps the most important. It looks like you have prior Kickstarter experience, but what type of experience to you have fulfilling KS previously?
Thanks
Compact Heroes was a successful project, and I fulfilled personally shortly after the end of the campaign. I had all the decks printed and shipped to me, which I shipped to everyone else. Thanks to DTRPG now, its' way easier. If you back a digital level, you'll get a link to the digital products right away. If you backed a hard copy, you will get a link to DTRPG and they will print and ship to you directly. That's why the backer level for the hardcover book is only $30, because you'll have to pay production costs+shipping yourself (as explained in the campaign). As of a few weeks ago, that would be between $45-$50
total (your backer cost, then $13 for production, then a few$ for shipping). Which is in alignment for what a typical hardcover 330page book + pdf would be.
Another question. Will there be licensing for other creators to publish adventures/supplements/etc.?
Since I'm using OGL, I can't license any of the mechanics. So I'm taking an approach of "anyone who wants to create stuff for this can. Knock yourself out". As an old school gamer, I am a fan of of fan created content. It's how we all did it back in the day.