Surprised there wasnt one of these here already, so I thought I'd just make one.
Similar to the monster thread, just give some thoughts on spell balance as it is currently! Either for individual spells, entire spell types, or specific classes. There's definitely some screwy balance issues with some of these, so I figured this would be a good idea.
So let's see here....
Rocket spells: The only ones I currently consider entirely useless right now. These are, at least in my view, really terrible. The only thing they help me do is blow myself up. As far as I'm concerned, a class with a rocket spell is a class that actually only has 3 spells instead of 4.
Touch spells: These are good for the Shallows areas.... but that's about it. I know they're also meant to stop enemy shots, but I've honestly always found them useless for this. The hitbox and the timing and all that is just too screwy, most of the time it just leads to me taking a hit, so I ignore this aspect of these entirely. Only use them in the shallows.
Whips: Sorta the same as the touch spells.... good only for the shallows. There's the armor-breaking, but.... never really found much use for that. Particularly since the damage of these just seems very weak. At least the touch spells can be fired more rapidly.
Seekers: I forget what these are actually called, but they're the homing shots. They're very, very situational, and they actually seem to glitch out alot; sometimes they'll fire BACKWARDS, and completely ignore an enemy that might be right in front of me at varying possible distances. Their cooldown is really nasty.... gotta have a very specific sort of situation indeed for these. Dont use them all that much, but they're decent at least.
Sliders: These are pretty useful. Great against crawlers of any sort. I seem to remember some versions of these where the caliber was a bit too high though.... a spell with as much utility as this already has should probably always have a very low caliber.
Sines: Another good utility style spell. Super useful in towers, often not easy to hit with though. These seem well-balanced to me.
Bombs: I use these whenever I can. I suspect alot of players wont use these much, because they're rather strange compared to other spells, but I use them for basically everything. LOTS of possible uses balanced out by being difficult to learn to use.
Campfire: Why arent there more defensive spells in the game? That sort of spell is pretty neat. Campfire is useful without ever being overpowered. Same with that water ring ammo spell, which has alot of the same uses.
Fullisades: Honestly, these may as well be straight shot spells. There's not THAT much difference in possible angles with these, and I've never found all that much of a practical use for them. Not sure what could be done to make these more useful....
Those are some that I can think of right now.
As for actual spell classes, any class that has two straight-shot spells should probably be changed. There's a particularly awful one in the tier 1 set, it's an entropy sort of thing, has two straight-shot spells and a touch spell.... very bad class, definitely the most useless one I can think of. Shouldnt be two straight-shot spells in any single class though, as there's not all that much difference between that sort, so you end up with a class that just has less possible uses.