If you've read my Top 60 list, you'll know I think rather highly of the game Spongebob Squarepants: Battle for Bikini Bottom; a 3D platformer that is not only a great representation of it's license, but a great game in it's own right. The game has a very active speedrunning community, and now thanks to fan-made tools like the Industrial Park editor, it's gaining an active mod community as well.
BFBBMix (pronounced with the emphasis on the final B, to rhyme with 'remix') is a full-game ROM hack by Sky Weiss that completely retools all the levels, dialogue, story, music, and even the boss fights from the original. It even incorporates some QoL fixes into the game.
The level design here is generally very solid, with some clever ideas being introduced here and there. As you may be able to see from the images included, a lot of the level geometry here is very simple, with a lot of simple rectangles, circles, and cylinders making up a lot of the levels alongside reused assets. It stands out a little more compared to, say, a SM64 mod because the textures here are more detailed and organic, but ultimately I don't think it hurts the gameplay at all.
One change in terms of the general flow of the levels is that they are much more vast and open than the original BFBB. I like this design change, as it cuts down on the use of loading zones and doesn't seem to negatively impact the performance much (there are a few places in the game where the framerate dips slightly but it wasn't enough to annoy me, and I'm usually very particular about framerates). However, there's also some smaller, tighter areas with an emphasis on sharp platforming; the first area in the redesigned Downtown Bikini Bottom is a very cramped residential area where you scale the buildings by jumping between different ones at different elevations. It's pretty cool, and I think the game gives you a good mix between open exploration and tight platforming segments.
Some of my favorite examples of creative level design is found in the bonus stages. These replace the spatulas that Mr. Krabs gives you in exchange for shinies, and are little self-contained challenges that often have new mechanics that are unique just to that challenge. Some examples include wind physics in Rooftop Rumble, playing a game of simon says in Patrick's Puzzle, or, what I am the most impressed by, Switchy Business, where you automatically switch between Spongebob, Patrick, and Sandy every two seconds and you have to time your actions based on which one you need to be at any given moment.
Now, let's talk about bosses. This was one of the criticisms I had of the original Battle for Bikini Bottom, that the boss fights were too slow and easy and just felt way too tedious. But the boss fights here were given completely new AI and function in entirely different ways, as well as providing much more of a challenge. Robo-Patrick in particular was very difficult, but none of them feel outright unfair.
The first phase of the final boss was amazing conceptually: basically to hit Robo-Plankton, you have to go through a short platforming gauntlet. You have to hit him nine times, and each gauntlet is based on a level in the game, and uses hazards associated with them (the Goo Lagoon section has rising goo, the Mermalair section needs you to hit switches to progress, etc.). It's one of the more clever final boss concepts I've seen.
Despite being designed primarily by a speedrunner, you don't need to know any exploits or speed tricks to enjoy this game. The only time I would say there was a required use of a mechanic a casual player may not know about is during the corridor to the final boss, which requires you to double-jump off of a bounce pad in such a way that conserves your momentum. It's not even remotely difficult or anything, but it took me a few tries to figure it out just because I didn't think the game would just assume you knew about that.
From what I can tell, the soundtrack was also made by Sky Weiss, and is comprised of chopped-and-screwed remixes of BFBB's soundtrack. I was unsure at first since I don't usually like that style of remix as much, but they're all really well-done and give the soundtrack more impact, and makes the whole experience more exciting. Link to check it out here: https://bfbbmix.bandcamp.com/album/bfbbmix-stereo-soundtrack
All the dialogue in the game has been rewritten to fit the story (which I guess the story is that Plankton trapped everyone in Spongebob's ventilation system?), and since obviously they can't get the Spongebob voice actors for this mod, it's all done through subtitles only. The writing is mostly good, lots of references to Spongebob in general as well as the original game. I would say it feels a little off, though. The humor doesn't quite fit Spongebob's usual fare and I have a hard time imagining some of the characters actually saying some of these things, but it is actually funny sometimes and I give them full points for effort.
Oh and since we're already in spoiler territory, guess what the reward for 100% completion is?
THAT'S RIGHT IT'S A PICTURE OF THE DEVELOPER'S CATS 10/10 BEST GAME
Overall, I very much liked this game. It's a little rough around the edges, but I wouldn't necessarily expect a ROM hack to have the same level of polish as a retail product. I think if you've played and enjoyed the original BFBB and want a new experience... well play the movie game because it's basically a direct sequel, but also play BFBBMix because it's an incredible passion project by dedicated fans that's sure to impress.