over all, very solid as a demo. bugs: only one major one, game freeze/crashed seemingly at random.
other issues: reloading the game basically removes all bought atoms, which would be fine, except it doesn't reset the price as well. (easily fixable by just adding all atoms together to see there total, storing that, then spawning the atoms at there most fussed). also antimatter is a bit bad because it can connect without player interaction which can destroy a atom the player wanted to keep (easily fixable by making it only enter the "combustible" state after the player launches it manually).
pros: allowing early gain of multiple prestige points at once is super nice as a QOL. overall game play loop is fun. upgrades are all fairly unique/varied.
personal: it feels like progression is a bit slow. even after a few prestige the growth scale only changes from the thousands to the tens of thousands, which is a bit disappointing. (one thing other games do is include achievements that give boosts as a reward)