Japanese version is 3.5 stars because the final boss has a new phase that is hella fun. It's otherwise a fun if stale platform brawler.
Unless you're trying to do a self imposed challenge of collecting as many coins as possible, they aren't as important as the game makes them out to be. Their only uses are to get garlic from that italian dispenser to restore health, as well as respawning at the point of death.
However, the amount you'll pay for both of those situations is almost negligible with the amount you'll find in the levels. Apart from those two things, the coins have absolutely no significance to the game's progression, ironic considering the significance of them to Wario.
Unless you're trying to do a self imposed challenge of collecting as many coins as possible, they aren't as important as the game makes them out to be. Their only uses are to get garlic from that italian dispenser to restore health, as well as respawning at the point of death.
However, the amount you'll pay for both of those situations is almost negligible with the amount you'll find in the levels. Apart from those two things, the coins have absolutely no significance to the game's progression, ironic considering the significance of them to Wario.