Nice game! I played a steam demo and want to share a feedback!
1. I think there are too much things to keep track of and I quite feel overwhelmed: so you have cores which you get each 5 turns and you buy shop boost from shop - two systems for identical reason.
2. Also, it feels like you overengineered the cores - discriptions like "Once per battle, when there are 6+ enemies, all enemies take 5% of current HP (Lv.1)" literally require a C++ compiler in the head to understand. Could be replaced with "All enemies get 5% more damage" for fun-focusing design.
3. I lack the "queue" system for units. So it's sertanly more profitable to keep your battlefield full (5/5), yet you always need new units for absorbtion. So right now the game forces to do spin->absorb, then spin->absorb several small loop during one wave. Would be more convinient to spend all coins in slots -> get lots of units, then disrubute them into battlefield.
4. The art, sound design and idea are quite impresive.
