Hmm. I don't know where to comment on the hack besides here on youtube. I've been playing through the game with the hack. I just finished the dark rift. I'll give you my opinion on somethings I don't agree with/bugs. Whatever I don't mention you can assume I think is done well. If I do mention something positive it is done really well.
I think you adding enemy's to some boss encounters is a really good idea. However after the beginning portion of the game I see a lot less of that from the hack. I feel either you haven't gotten to doing it, or the game just doesn't allow for it on certain bosses.
The second boss in the game. The sentinel on shrine island. I feel like he is far to difficult. He is beatable yes, but only if you grind out. I was level 8 when I beat him and I almost lost that attempt. The Grouders do way too much damage/confusion is too punishing with 2 characters. I would either reduce the number of Grouders, reduce the Grouder's stats, or change the enemies for that boss encounter.
Due to the nature of this hack, I think you should modify the risen spell. At the very beginning of the game you can lose a character. At that point you don't really have the tools at that point in the game to deal with a dead character besides relying on luck with Risen. If possible I think it should restore 25% hp and work 100% of the time. Same with Risen crystals. I've lost several fights due to just being unlucky with the spell/risen crystals. I have some experience with hacking the dreamcast version of the game and I can't confirm if you can do this, but it doesn't seem like an out of reach idea. I know you can modify special moves damage and costs.
Enemy quick. I feel it is way too high. Even when you over level, non-loopers are still faster than you. They are still faster than you when you use quicka. This makes it way too difficult to react.
Enemy's "level" stat. I don't remember if enemies have a level stat, but remember when I talked about being over leveled? Well, after you level too much in a area, a lot of enemies just try to run away even though they are fully capable of killing your characters and still not easily killed. I would do something so that enemies don't try to run away from you until the player can probably kill those said enemies easily. Unless you have a black map it might be really hard to grind at all and having to grind seems required (which is fine, just enemies running from you makes grinding annoying). Also when you have a black map and enemies try to run away and it fails, they are defending for the duration of the turn. This makes fights a bit longer because the enemies are just defending until dead.
Antonio 2 boss. I killed 2 of 3 of them then the music stopped for some reason. I don't know if this can be fixed.
I would make the enemies in Daccat's island a bit easier or at least the spawns a bit easier to account for less characters. I ran from fights most of the time there even though I was around 26 or 27 ish (I was 2 or 3 levels ahead of Gilder). I would make the boss a little easier. One attempt on the boss they cast both Death Waltz and Explosion on the same turn. Aika and Fina died with full health and that was pretty much the end of that attempt.
It says Agi II in the menu I think. All I know is there is a some text errors.
Can you port your hack to the US version instead of the PAL? PAL runs at 25 fps, while US runs at 30 fps. Or can you change the PAL version to go at 30 fps? I know some games were hacked that way for the Gamecube.
The battle of Maw Tarras when you have the Little Jack is ridiculous if you are unlucky. They can just grenade spam you. If they decide to there is very little you can do about it. Of did you know the Valuan soldiers in the first dungeon at least on the dreamcast version can be made to cast grenade?
Bounty bosses. These guys have gotten more difficult as I leveled up in the game. I almost beat Rupee and Barta at level 18. I almost beat them in the early 20s. In the late 20s melee attacks no longer hurt Barta. I think the Bounty bosses are a bit overtuned. I don't mind them being difficult, but I feel like I now have to make preparations (use seeds) just to beat one. I don't think fights should get exponentially harder as you level. I don't mind them getting harder, but they are getting more stats than you are from what it looks like as you level. I think they should get slightly easier as you level even with them gaining stats. I feel like even with Enrique's Justice shield these bosses will still one shot you. Barta I think was capable of doing 9999 damage when I was in my late 20s. 4k+ when blocking (note I didn't have 4k hp with anyone at that point).
Piastol battles. I didn't and still don't stand a chance against her first fight. Since you have to fight her several times you should probably make all but the last a lot more feasible to deal with early on.
From what I read with the tips. I feel like the optional bosses/late game is all balanced around Enrique and buying seeds. I would change this. I would attempt to change what justice shield does or if that's not possible nerf it by making it cost a lot more SP.
That's all I can think of for now. Good luck. I'm really enjoying the hack and pretty much like everything else.
I did leave this in a youtube comment, but I think its more likely you will see it here.
Edit: Optional bosses are fine. Didn't know their stats cap out at a certain point.
Edit 2: The Hydra is WAY overtuned. I can't beat it, no matter how hard I try. On the round Hydra cannon becomes available to the boss, on turn 3 of the round, he attacks and does 15k-25k damage, he then hydra cannons on turn 4 of the round, me defending I take over 30k ish. Next round if he goes first on turn one it's a loss every time if he attacks (another 15k-25k damage). If I defend on turn one of that round, I'll survive, then die on turn 2 of the round if I don't go first. Right now I think the only way to beat him is luck by going first. The only way around this scenario is Pinta which you can only use once per fight or a hex shell maybe which I only have one of, but this scenario happens every few rounds. I tried giving my ship more defense, but it has very little effect and doesn't change the outcome of that scenario. Out of the 8 or 9 times I tried, my best attempt was getting it a little passed half dead. Most of my deaths were to that scenario.
Edit 3: I defeated the Hydra. I switched some of my ship equipment to quick/dodge pieces. I still didn't go first every time when I needed to. Doing this just improved my luck of going first. I needed to use the Hex shell though. I still think you should nerf this boss regardless. Way too much damage from the boss or you could nerf it's quick.
Edit 4: Finished the hack, beat every boss.
The hardest bosses for me was Rupee and Barta for normal bosses. For ships Hydra (by a lot).