The gameplay was great, really fun despite being very simple. It's fun picking up all of those passive skills and seeing your character and Marigold become super powerful. I also liked the music and the theme was implemented perfectly, as well as the two bonus challenges you chose to implement.
Have to say though, the sacred orbs seemed pretty useless. And there's three type of sacred orb skills with four levels, so it's a lot of investment for almost no gain. Even when you have all the orb skills, they either rarely hit anything or just push one enemy away each "at best" and at that point there's literal swarms going after you. They need to be buffed somewhat.
Marigold's HP also keeps regenerating even when the game is paused during ability selection, so you can just wait until she gets healed to full. I don't think that's intended, And if it is, maybe have her just regain a portion of HP instantly instead of regeneration it normally.
If you want to work on this further, maybe you could add a "Story Mode" that adds some kind of boss fight at round 150 and an ending when you defeat the boss.
Also, some kind of super-ability that only gets unlocked when you max out everything else would be kinda cool.
Also, one question, what did the Absorption Ability skill do? Did it push monsters away, since the icon seemed to be a magnet?
Anyway, great game, by far the most fun gameplay out of all the ones I've played from this game jam! I'd definitely play an expanded version of this, a sequel or another game with a similar concept.