Hi Capital!
The interact button was bugged in 0.6.9 and has been fixed in the subsequent build(s).
• You can interact with Gidgit on the training stage after beating him to have sex with him
• You can interact with Kate on the training stage for training lessons
• You can interact with Vitki on the debug stage for light cameo dialogue
• You can interact with certain special NPCs that appear in stages for upgraded items