This kind of grinding strategy is potentially possible in:
All main stages except TR1 and TR2 (respawning wisps)
All main bosses (only a hit to their weak spot will kill them, so you can keep getting non-fatal hits)
Terminal Velocity/Nega-Wisp Armor (just keep hitting him in the drill phase; perhaps the least time-consuming one)
Fot all Score charts there should at least be a Time Over requirement.