Wow, you’ve got a sharp eye for design! The synergy between upgrades (like Echo and Oblivion) is indeed rooted in our Skill Stack system—where even negative skills add strategic depth. A speed-adjustment option (alongside volume controls etc.) is coming in the next few weeks! We’d love to hear your thoughts after major updates. 🚀
Yeah, it's like "Do I want a good upgrade, or a middling upgrade that I can feel good sacrificing to the Event gods, or a middling upgrade that gets better and better every time I sacrifice it to said Event gods, or a fantastic upgrade that replaces my next level up with fodder for the Event gods, etc. etc."
Basically, Events have done so much good for the texture of this game, helping you achieve bigger scores and combos through at least two new angles.