I haven't played it beyond the Kylearan's Tower, because i had not time to do it. But i want to address one point of felipepepe's criticism: 2 round fights.
Fuck have you played BTI-III? If not then i recommend to you to play the remastered version to see it for yourself. Every fight in BTI late game is just 1-2 rounds long. I needed just one Round for the 4x99 Berserkers and for Mangar i need just 2 rounds.
So what? Their combat systems and encounter design are entirely different, nothing that applies for one serves for the other. Why are you even bringing this up?
Because the critic that you apply is also part and the appeal of the entire BT series (with the emphasis upon MIBL, MAMA, FAFI, JOBO, NUKE) and the sequel is measured upon and compared to the predecessors, like in the case of Fallout or Ultima or Wizardry or etc series.
So you have figured out a combo and build that lets you spare resources and win major or minor (i get from your review, that this were minor fights ) fights within 2 rounds. Good for you. But this was not different for the majority of fights in BTI - III.
Think what you had to do to win the 2 round fights in BTIV and what was in BTI: R1(AAHU(Fire Horn)C(MIBL)C(MIBL)), R2(AAAU(Fire Horn)C(MIBL)C(MIBL)) (here spot the difference between R1 and R2).
I don't know how you played up to Kylearan's Tower without figuring this out, but this is not a real sequel. Besides the setting and a few spell names, it has fuck all to do with the previous games. I mentioned this at the start of the review and said I would judge it as its own thing.
Because, as I mentioned, the logic is entirely different. Bard's Tale I-III are games about attrition, even more than Wizardry. Individual battles are meant to be extremely fast, but they will force you to spend spell points, decrease your HP and fuck you up with status effect, until you're forced to go back to town and spend a fortune to restore your party. Combat in those games is actually extremely simplistic, the entire gameplay loop hinges on exploring as much of the maps and gathering as much XP and gold as possible before going back - be too ambitious and you die, be too cowardly and you might not have enough money. At least that's the idea, because those games had some ludicrous balance mid-game and the solution becomes "grind like hell".
Meanwhile, Bard's Tale IV has one save totem that fully restores health every 5 minutes, has no status effects that carry between battles, spell points are per battle and the game is filled to the brim with food & healing items. Your party is basically always at full power, there are no resources to manage or spare. Moreover, it has several spells and abilities that require channeling and/or saving mana, meaning you need battles to last multiple rounds, or those abilities are just useless. Even the speed is entirely different, you can do like two entire BT1 battles before even the passive buff animations play in BT4.
That's why Bard's Tale 4 encounter design is retarded. Maybe the designer was bright like you and didn't figure this out, but they are operating under entirely different rules, pacing and concepts. BT4 battles need to have much more weight and challenge, since they are self-contained. Instead, they can be won just as easily, carry no consequence, take longer and have way less variety than even BT1. There's nothing like a dragon fucking your entire party up with his breath, spiders applying poison, vampires draining levels, etc. That's why it sucks.