Okay... I think I've come down enough to form...words...again. So...wow. That was...something.
Okay, so under normal circumstances, I would take a fanimation like this at face value, give my two- or three-word opinion on it -- usually in the form of a YouTube comment -- and leave it at that. But I can't really call these "normal circumstances" because I'm not dealing with something that can be considered "normal". For that reason, I feel it necessary to go into extensive detail about what I think of Double Rainboom and give my overall critique that way. Bear in mind though that this is probably the first thing I've ever done that constitutes a "review", and I want to make sure I cover my bases as well as I possibly can. To that end, I'll be going over each aspect of the animation that should be gone over. May Celestia have mercy on my soul.
Also, as this is, after all, a review, I highly recommend you watch the video above before reading, as there will be spoilers. So don't say I didn't warn you.
Twilight makes a talent-boosting potion. Rainbow Dash drinks it. Okay. I'm down with this so far. So, what, Dashie causes trouble with her newfound speed? To be expected, pretty "formulaic", I guess. Rainbow Dash punches a hole into another dimension and...winds up in...Townsville? ...What? Okay, as the type of watcher expecting a standard Friendship is Magic fan episode, I can't have seen this coming. How could I? Personally, I wasn't sure what to make of this at first. Yes, I love 90's Cartoon Network and The Powerpuff Girls, but I went into this expecting Friendship is Magic, not a crossover. None of the previews and trailers so much as eluded to this being a crossover, and I suppose I respect the production team for making that twist a surprise. But in my opinion, it's a bit TOO surprising, and maybe a bit jarring. And really, once the double rainboom happens, everything Friendship is Magic-related kinda takes a back seat. I know Rainbow Dash is the focus (hence the title), but the only other major players in this are Twilight and Pinkie Pie; Applejack, Rarity, and Fluttershy don't so much as say a single line. Now, that's not to say I didn't enjoy the story for what it was. Like I said, I loved The Powerpuff Girls, and seeing them here, however surprising it was, was a nostalgic treat. But in the grand scheme of things, the double rainboom was more flash than substance, there was nowhere near enough involvement by the rest of the Mane Six (did any of them even notice Rainbow Dash was missing?), and Rainbow Dash's interaction with the Powerpuff Girls boiled down to "TALKING FLYING PONY! CAN WE KEEP IT, DADDY?". Oh, and let's not disregard Rainbow's friendship lesson in the end: don't take stuff that doesn't belong to you. Um...okay? Great lesson and all, Dashie, but you just went on a journey through time and space. Surely there's a better lesson here somewhere if you look hard enough.
While the story was a bit of a clusterfeather and the lesson kinda lost in translation, I can't in good conscience fault the writing as much. The Friendship is Magic part of the story really did feel like a legitimate Rainbow Dash episode and everypony was very much in character (mostly, but I'll get to that in a bit), and the Powerpuff Girls half felt like standard Powerpuff Girls fare. I honestly felt like I was watching the movie again and I was watching the Townsville-wide game-of-tag scene. I especially enjoyed Scootaloo fangirling over Rainbow Dash and Bubbles naming her Antoinette. And while the PPG sequence was a bit trippy, Buttercup's cry of "YOU'RE NOT A PONY!" at the Talking Dog made it well worth it. Not perfect though; I felt there were more pauses in dialogue than necessary (and honestly, the writer passed up a perfectly good "double rainbow all the way" joke). But a lot of the jokes and continuity nods were nicely timed, well-placed and, again, in-character for those who made them.
Okay, now we're getting somewhere. There wasn't as wide a cast of characters as I feel there should've been (seriously, no lines for three of the Mane Six whatsoever), but for the characters we DID get, I think the cast did a pretty decent job, especially Kira Buckland as Twilight and Eileen Montgomery as Bubbles -- I could swear I was listening to Tara Strong. None of the voices were at all bad or cringe-worthy (Isaiah Kim does a terrible Tom Kenny impression though XD), but in a couple of instances, I thought Twilight's voice had gotten a bit too whiny.
Do I even need to explain this one? For a fan-made Friendship is Magic episode, the animation is 100% spot-on. Character animations and movement are just as fluid as in the TV show and don't look stilted, facial expressions are very expressive and amusing, environment are stunning, and the animation/effects for the sonic/double rainbooms are amazing. Nuff said.
As with the animation, I don't think I need to explain this much. With a musical score provided by MandoPony, how can you lose? The set pieces are very fitting (with Rainbow Dash's lines and scenes punctuated with sweet guitar riffs), and Mando does each show fantastic justice with his signature style. And the little things like the Back to the Future and Foster's theme bits were a great touch.
Double Rainboom: Was it good? Not as much as it could've been (I place considerable blame on expectations). But did I enjoy it? Very. I think anyone who's a fan of either Friendship is Magic or The Powerpuff Girls (or both) will find some enjoyment in this. The unnecessary breaks in dialogue, bizarre-as-hell story, and slight overuse of fandom nods may take the avid fan out of it a little, but the decent voice acting, fantastic animation, and great music make it pretty enjoyable, especially for those suffering from pony withdrawal. For added entertainment, picking out and identifying the individual continuity and fandom nods can be fun, but there's a lot to be found (many of them blink-and-you'll-miss-it moments), so I hope that's not a deal breaker.
So that was my first proper review of something. Hope you enjoyed it, and if you didn't, feel free to burn little wooden pony figurines of me in effigy. If it pleases the court, I may do another one of these for Snowdrop and other MLP fan-made stuff I like or is requested of me. (I will never read/watch Cupcakes though. I cannot stress that enough.)
I'm ImperfectXIII, and this has been an Imperfect Review.