Last week I was playing it, I leveled up and clicked them "remove points" button by accident before having assigned any of my extra points to anything. My available points count became 9999. Tried the same thing with abilities, and it worked again. I have a level 22 character with 99 for all stats (skill is 124 somehow, I don't know what I did there), and 24 for all skills.
Something else that just happened is, I died at the same time I leveled up (I hit an undead dwarf at the same time an eye stinger hit me with it's flare, or possibly hit us both and finished the dwarf), so I thought I'd try to click the level up button even though the Game Over screen was on. It worked, and when I exited the level up screen my hp was back up to 240 or something, close to minimum but still more than I could have regenerated in the few seconds I was in the level up menu. The game went on as normal and I ran off from the Nexus, my eyes rimmed with glistening tears of joy, my pants fully crapped.
This game is unique in how helpful almost every single glitch is. I only know about these two, the Oliphant level up glitch and the access-locked-chests glitch, but they all make me laugh in my heart as I plow through this game like some sort of retarded god.
Attempts to repeat the level up points stunt have failed. There must be something else I did which I cannot determine right now. However I got hit with another glitch, or possibly not a glitch, and this one not terribly helpful. The Glove magic apparently continues to drain MP even after it has been depleted, but without providing the damage reducing bonus, it takes your MP into negatives fast. And you can't seem to stop it, even when you remove it from the shortcuts. It seems to stop when you save at a save point. I have to confess I don't fully understand how this magic works exactly.
Also, I collected undead body parts repeatedly, although it didnt count for anything, and I had some fun times with faulty conversation triggers with Livingstone and that angry dwarf general in the dwarven courtyard AND Nobbler. I am absolutely NOT knocking this game, in fact it's one of the best ds games ever made. Its just rickety.
This will be my glitch report board from now on. I fought Zagor just now and I managed to fall of the platform onto the lava floor, the platform itself becoming transparent. I beat the crap out of Zagor's cardboard cutout from underneath and then walked off the edge of that and fell into the blackness for a while. It was nuts. This game is siiiiiiiiiiiiick