Since this is a playtest doc I'm looking for all the feedback I can get. I would absolutely love to hear anything you think about my game. Even harsh criticism is welcome and if you find errors or major rules issues then you'd be doing me a huge favor to let me know. 

If you get the opportunity to sit down and play with a group, please let me know how it goes! I would be thrilled to hear about how your session went. 

I really like this!
Typo:

"A Final Release requires you to empty two full Heat gauges and has two effects: it immediately refills your Energy pool and lets you roll and keep five dice!"

I've heard about this game about a dozen times before I checked it out, and I find that it's a stellar little system with a very good presentation. Some immediate notes:

1. Mentions to 'Awakened' and 'Monstrous' Power levels have 5 mentions each in the Pre-Penultimate, these seem to correlate with Legendary & Titanic
2. I'm unsure if I'm not parsing it correctly; however, in an uneven Engagement: consider a 1-vs-3, would the 1 individual on Side A act between each individual on Side B? This seems relatively salient, but I would understand playing heroes & monsters in either configuration (where each Side has 1 action per individual, or each Side gets to respond during each section of a Round).
3. Earning Advancement Points (Pg. 34, bullet-point 4), is this "first time in a session," a scene, or a campaign that someone powers-up to the next level? I can see purpose & reason (given a story) for each of those three configurations as well.
    3a. Spending your AP (Pg. 34, bullet-point 5), the phrase "Signature Power" appears, & is only mentioned in this entry; I take it to mean 'Tech?'
4. On Pg. 27 (covering the Fighting Spirit trigger, Outnumbered and Outgunned), the word Extras appears here, as well as on Pg. 83 on paragraph 11, under the GM: speaking tag.

On Releases: is there a benefit to taking a Secondary Release over using two Primary Releases, or would the benefit be the transient gain of a single die over the Primary one? Should it restore 1 or more points of Energy?

I absolutely adore this & everything you've done with it. I understand that you mentioned a number of days ago that you have another version you'll be working on and, quite frankly, I'm thrilled. I'm looking to pair it with a few non-combat systems and just making some immense cultivation-style world-building game. The Techs are phenomenal, and your inclusion of the sample Techs is super appreciated.