Frankly, all you need to do to actually *beat* the new fight, at least on Sam, is just maintain your distance from the Suit machine that drives around, and ultimately just keep dashing through the boss and Whispy by holding down space. It takes a bit, but the burn damage you accumulate onto them alongside the minor damage you deal will add up in time and lead to a pretty easy victory. Frankly playing this way I imagine most of the games enemies are pretty easy, I remember struggling overall a LOT more with the garden boss than I did with this one, though if I did actually attempt engaging this one it'd get pretty tricky pretty quickly, as its basically just a LOT of managing aggression and distance given its effectively a three mob boss fight.
Figure its probably more difficult on Whispy in the end, but for those who want an easy and pretty guaranteed way of winning, play Sam and just always keep yourself a decent bit from the rolling suit machine, taunt when needed to build back stamina and heat, and just hold down the space bar by and large and you'll be fine. You're completely invincible, do minor damage and can inflict burn while doing this, so it just really becomes a waiting game at that point.