Thank you for playing and for the detailed feedback!
I've pushed a patch addressing some of the issues you mentioned:
Skill chain not firing: The attack cycle timer was ticking even when no enemies were in range, causing chains to "waste" their cooldown on empty shots. Now the timer holds until enemies are within range and fires immediately — this should fix the inconsistent 3-second delays you noticed.
Nova freeze: The stutter was caused by a light texture being regenerated from scratch on every Nova activation. It's now cached, so multiple Novas should run smoothly.
As for the early-game difficulty curve and the gold penalty feeling too harsh to get meaningful upgrades — that's valid feedback and something I'll be working on in future updates.
Thanks again for trying it out and for the encouragement!