As you can see I am missing one of the stars despite playing this thing through 5 times and finding all at least twice.

Link to game

1. B
2. A
3. C (star)
4. C
5. B
6. A
7. A
8. C
9. A
10. B
11. Lower left
12. A
13. A
14. A
15. C
16. B
17. A
18. A
19. C (star)
20. B
21. A
22. UPPER RIGHT
23. B
24. B (star)
25. C
26. B
27. C
28. B
29. C
30. A
31. B
32. B
33. lower left