1. He may have gotten up late.
2. He may have a fever.
3. He may be running towards school.
4. he may have forgot to come to school.
5. He may have overslept.
6. He may be spending time playing computer games in a PC room.
7. He may be upset and doesn't want to come to school.
(Are the expressions grammatical? Would you check them? Have a good time.)
All are fine.
I'd use "game" instead of "PC" but the sentence is fine as it is.