I'm having a difficult time articulating exactly what seems so wrong about the whole thing to me, but it seems like some of its core issues in short are:
- 1. There aren't nearly enough monster roles. They at least have the sense to not divide stats up by creature type, but the only possible roles are Combatant (stabs or shoots things in the face), Spellcaster (the bomb), or Expert (overrated for actual combat threat). So your options are "it's basically a simple sorcerer" or "it fights people", and those are at once too broad and too narrow.
2. Ability scores are totally unlinked from everything else the creature does. They're seriously only used for determining skill check and ability score check bonuses. What the fuck? There's actually no reason for a giant monster to have a good Strength score other than to be good at climbing and swimming. Strength has no impact on its ability to grab or pummel people, and if it wants to break stuff it just has arbitrarily high damage to attack with. Monsters are seriously best off just picking Dexterity to be good at hiding and Wisdom to be good at finding people. Everything other than 3 of their ability scores are just automatically 10s for some reason.
3. The ability lists are not even close to valued accurately. It costs the same amount of monster resources to have channel resistance as it does to force a save versus being paralyzed on every natural attack. WTF?
4. There is no level gating on abilities other than spellcasting. Constant greater invisibility, sneak attack, and Far Shot are all equivalent abilities available at CR 1.