I decided to start learning stage 2 for score, and was up until 4am doing so
I have managed twice now to full chain the stage, so after a bit more practice I'm gonna try for the loop. I think playing this for a month has made me realize this is one of my favorite shooters. Its crazy how different stage 2 feels once you know why every enemy and bee has been placed where it is. The game is so matoculously designed, its brilliant.
Oh, and for the collecting bees requirement, you also have to not die from the time you pick up the first bee to the time you pick up the 13 bee. You'll know you did it if the 13th bee's score is in gold instead of red. So, you can die on bosses (aside the 3rd boss, which has 2 bees you have to collect first), and you can die before the first bee, but thats it.
I think the chaining req is the most achievable. That hallway in stage 5 doesn't even require any thought to chain, you just have to avoid bombing.
