Intended to first play this with a group of friends alongside some additional game-twisting mods, but tried several courses solo with the interest of writing this here review. This mod isn't anything groundbreaking, but it does do as advertised: rain random items and mobs upon every course. T'was tamer than I anticipated, for it takes a while for the limited assortment to really pile up on you, though luck of the draw can still easily make or break your missions. T'was also pleased to see how well the rain adapted to indoor courses; the same cannot be said for underwater, where every enemy either dies or sinks. The uniquely-coded 'Star Shield', that was another pleasant surprise! Until it stopped me opening doors or grabbing Bowser.... oughta give it a time limit to prevent such softlocks.
If there's anything I do want to see, it's more possible items and enemies to freshen things up, especially the weird sorts such as Pokeys, Moneybags, Mr. Blizzards, Fly Guys.... Chuckyas 'n' Heave-Hos would be especially naughty, while Skeeters and Cheep Cheeps can solve the problem with water levels. (the latter could flop about if spawned on land)
One more idea to round this mod out: chat commands that'd adjust the item spawnrate and probability pool, so those fancying extra-chaotic escapades are free to take things up a notch.
Overall, I'm left feeling neutral, with an even balance of pros and cons. I'd say it's worth a try for challenge-seekers who desire a level of spiciness below the infamous Chaos Edition, but above randomised warp nodes. Just beware the deformed Dorries of the Hazy Cave....