I got it down to 6.4mb post-jam! I'm not sure what you mean about bubbles of different colours getting wrongfully removed though - it correctly matches the colour and plays a pop animation, then any bubbles that are no longer attached to the top fall off. That's intended, and it's how you get higher scores!
As for the lag, it was a lazy bit of jam code and I'm really annoyed with myself for it 😭 I fixed that straight away: https://www.crazygames.com/preview/bc56318b-77bf-4646-aca9-c3f5012f4b70