Game-breaking bug

[Ninita]

I'm at the part where you need to get 3 colored key by beating 3 big robots to open 3 colored doors.

I beat the robots and got the keys but they aren't shown under my life bar (the ffirst one was but I didn't noticed if the others were too) and, when I get to the doors, I don't have any "press up to activate" message nor are the doors open nor does the NPC speak to me.