I made pretty good progress on Ace on the 7th level (I think, the second Phoebe level, whatever that one is). My favorite bit was finding this door, which led to a room with three closed doors, and an open door, and behind that open door was a red switch. When I shot the red switch, all 3 closed doors opened, two of them unleashing enemies. When I killed them, the third door had a whole area. When I went through the door, the area went into lockdown and I had to kill a whole bunch of bots in order to open the door back up. That part was pretty intense.
I had to stop to feed my son though. Hopefully I’ll have some time to continue tonight.
P.S. One thing I’ve noticed on Ace difficulty is you really have to use your missiles well, and use the right missiles at the right times. Otherwise you just can’t get through some areas. Luckily there’s lots of missile ammo on every level, so I’ve only run out of certain missiles temporarily, never for long. And if I’m using the wrong missiles for the job, I can have a really tough time in certain areas, and get through, but with lots of damage done to me.