Like in any Shantae game. you have multiable ending screen of each reason. If you are unfamilair about the design of the levels. Because they do change from each dlc.
1. Game Complete (Just Beat the Game).
2. 100 % (Collect all Dream Squids [3 per level]) This was basicly my playtrough run I did. So my time was like 1 hour and 6 minutes. So way overboard
3. 100 % FASTEST TIME (aka Speed Run) I don't know what the time is. But from what I read it's like a hour. But because I overused the option to save before the level start and with a mistake or a time lost. I quit the level and reload savefile and redo. With that option of Quit-Load-Success-Save option. Don't do it. It helps alot. Also it might help if you don't know the entire layout of the level or not sure how the game works. Do a casual play first and then try speed running. With my luck I managed to get a 00:36:?? on the timer. It was a nice run
4. FASTEST TIME (aka Speed Run, no Dream Squids needed) I don't know how this is the fastest way or the best
TIPS:
-Before the mermaid slide. Mid way the climb. Don't forget the dream squid. I did forgot it and had to go back. Lucky I used the quit and load option to save myself some time
-For the Mermaid Boss fight, jump up onto the platform. Usually you would jump towards Mermaid and get one melee strike in. Instead spam Ninja Stars with Circle button. Doing so you should be able to defeat mermaid in 1 to 2 (tops) cycles of the boss fight.
-After the climbing stage of the sand tower. You get a small gap. With my first run. i went the long way. But I found out in my speed run option. I went like dropped where you see the first Arrow harpy and used ninja teleport to grap in a instant the first dream squid. Was a big time saver.
-Teleport past enemies using Sqaure button. There's little need to fight regular enemies. Only stop if you see big jars so that you can destroy them quickly and level up your Ninja (which will deal more damage for boss fights). This helps alot around the final stage with the weird toad big cannon balls enemies. I was just enough space to get passed them without getting hit. Took me a big time to get it right.
-Also when going for speed runs skip all dialogue as fast as possible by mashing the Maybe the X button. But I used the touchpad. According to good Super man some scenes allow you to skip a series of dialogue with Touchpad, so try that first and then if it doesn't skip mash that X button!!
-(I haven't done this. But it helped me out to use the layout the casual playtrough to remember the platforms and then abuse the save file to get the decent run) If you still struggle for 45 minutes time, I recommend you do a 100% playthrough Speed Run followed by a Speed Run where you skip the Dream Squids. Make sure to start a new save file as continuing a previous save file from the base game or first DLC will add to your total time.
Here is a little video for just incase. But I made it like a spoiler. So make sure you wanna see it.