I sat down with the guys today to play this mythic playtest, and long story short, everyone had a blast.
We played with three level 5 characters: a dhampir two-hand fighter (champion), an aasimar cleric with a glaive (Hierophant), and a half-orc ranger (marshal).
The first encounter went generally well, though the monsters all had trouble hitting anything - agile wolf or not, it couldn't get past the moderately armored (all three were wearing breastplates and had moderately good Dexterity scores - the lowest AC was 20. It got three full rounds before it got taken down, and it didn't land a single attack, even though I gave it extra mythic points to try and let it land *something*. Perhaps it was just bad rolling.
From my side of the curtain, I found the agile template to be awesome. I love the idea of a monster fast enough to get multiple actions per turn, and it's done a lot better than actually getting standard actions are. The much increased land speed certainly took the players for surprise.
The second encounter was just gaining the tiers. I had already made the players look at everything beforehand, so this went really smoothly, though the first player thought Erastil,was asking them to eat the stag, so the Dhampir actually started carving it up before they touched the arrows. Pretty amusing.
The third encounter really impressed upon myself, and the party, how despite being mythic, they weren't invincible. The party split up, and the savage bears and their bleed damage took a fair toll on the party while the treant dealt it out in raw damage. The party was really concerned about spending any mythic points here. They're a limited resource, and they were worried about pressing forward if they spent them all. Like any daily pool, I suppose, but it was enough that they actually voiced a comment. Eight points in a day isn't that much if you might spend three in a single round.
I found Erastil's treasure very appropriate. A holy symbol for the cleric, bracers for the fighter, a bow for the ranger, and ... a cloak, which would have been awesome for a thief if there was one. The nectar of the gods was immediately consumed all around (good call!), restoring everyone's faith that expending mythic points was a good thing. By the end of this adventure, however, nobody had spent any mythic points on the items, though they loved the abilities.
The howling chasm was ironically the hardest challenge of the adventure, with Acrobatics and Climb being universal weak points in the group. After falling off the bridge a few times, they came to accept that they had to simply tie themselves along and eventually they did make it across. That 1d6 didn't make any difference here, and the players were already (after just recharging!) unwilling to spend their mythic points on skill checks, despite it being very clear that they needed it.
EDIT: I did forget that one of them did use a mythic point at the very end, when they rolled really badly to avoid being thrown from the bridge by the lightning. The point did save them, which I found awesome, and I described as grabbing the edge of the bridge after they had been flung over the side. Very thematic.
Then, the hydra.
It was a pretty awesome encounter all said, and they really found their synergies. Amazing Initiative basically doubled the duration of buffs, for which the cleric was super happy for, and the battle went pretty much like this:
Marshal: Decisive Strike to give the Dhampir another attack. Shoot with bow. Amazing initiative.
Champion: Fleet Charge to move and take an attack. Then, full attack to get two attacks. Amazing initiative.
Hydra: a few hits, nothing exceptional.
Masrhal: Same as before, Decisive Strike, shoot with bow.
Champion: Fleet Charge to 'move' and take an attack, then full attack to get two attacks.
Hydra: still has trouble hitting an AC of 22, despite being CR 9.
Marshal: Decisive Strike to give the Dhampir another attack. Shoot with bow. Amazing initiative. Take six bleed damage.
Champion: Fleet Charge to move and take an attack. Then, full attack to get two attacks.
Me: okay, sheesh, it's dead.
Heirophant: I only went once! heal check to stop the dhampir's bleeding I guess.
Everyone had a lot of fun, especially with the hydra, but in the end I felt that everyone realized really quickly that mythic creatures had more trouble hitting AC than normal creatures, and took advantage of that by putting a buffed fighter in front.
They especially loved how everything felt 'epic, but without having to roll a dozen dice or deal with modifiers in the hundreds', so I really have to give props on that.
If I had one major piece of feedback, it would be that mythic creatures need to get some sort of to-hit bonus without spending their mythic points. It was really visible with the hydra especially, that at a maximum of once a round, getting +1d6 (or +1d anything) really wasn't helping. It still had to roll a 12 before it was even worth spending the point to have a chance. A flat plus, even a small one, would probably have made a fair bit more of a difference.
Overall rating, 4.5/5 Very enjoyable.
I've got two more playests planned, the first at slightly lower level, the second at much higher - which will give me a chance to try out creating mythic monsters. I'll let you know how it goes.