Whilst it gives the flavour as Peri'Peri chicken, it doesn't mention with hotness level - there sure are some massive differences! I'm going to have to take a guess.
On first taste - there's a definite citrus tang that would pair it with lemon & herb, but as the flavour permeates through my taste buds I'm inclined to say that it's something hotter in there - the bell pepper hit is coming through and i'd put somewhere between a medium heat and lemon & herb. The chicken undertone is a classic chicken flavouring from Walkers. There's also a heavy amount of Paprika it seems, which does surprise me. You can see if in the colour of the crisp.
I'm less of a fan of the lemon so afraid it's a 6/10