Booster Hill is a minigame where Mario can earn flower points. The max is 15 or 16 flowers.
Jump on the barrels and snifit heads to touch Peach/Booster to get one flower.
The isometric view during this game makes it tough, as hitboxes seem to be non-existent sometimes.
14 Flowers is ideal to be set for the rest of the run if going for Smithy Chest Head Gamble; 11 otherwise (You need 24 FP total by Yaridovich. 26 is required by Countdown, but more FP may be useful in case of bad luck (36 is ideal for a worst case scenario on Countdown)). If you end up being short on flowers, there are other points in the run you can collect them.
Tip: In the barrel phase, stay up at the front at all times. Barrel frequency is constant, but where the barrels spawn is random.
Tip: In the snifit only phase, if you hit Booster, he will run far ahead to where you can't reach him. If you jump on a snifit right away, it's possible to miss Booster as he falls back to the pack. You can get another hit on Booster without missing a cycle if you wait slightly and try to hit a snifit as Booster is moving backwards.
Tutorial by Justin: https://www.twitch.tv/videos/201020547