I'm assuming you just pause and see what they do, then do something to counter it (dp!).
Don't really need to, though, 'cause the AI is so stupid that you can win with just dash 5AAAAAAA. It took me around an hour and a half to beat a course with a 39C fever and I have maybe 5 hours of total game time with P4U and P4U2. I assume for someone who actually plays the game, it's free.