Lego Ninjago has featured an inumerable range of mechs since its inception. 71707 Kai’s Mech Jet exhibits a different trend, though. A second model option is available. Perhaps this mech has something to offer after all.

Minifigures

Kai is the ninja in this set, and he is wearing this season’s themed garb. The digital elements are nicely printed on the front and back. I especially like how white was incorporated into the look. His right arm and double molded mask exemplify this characteristic. He has a double sided head as well. One side evokes some sort of heads up display and the other side conveys a shocked expression.

Richie is the other minifigure in this set and appears to be the antagonist. He features elaborate printing in several colors and a retro 8-bit design. I quite adore the little skull. He has a new double molded head which also incorporates the Ninjago regular, 6129476 Mini Pony Tail.

The Completed Model

Vibrant Coral plates exist throughout the mech. However, I was pleasantly surprised by their inclusion. I think they add to the overall design. It certainly seems to fit this digital world. The feet amalgamate the plates in layers for a nice effect. The legs are rather skeletal and assign the thighs to resemble knees. The core is structured excellently and, despite its routine format, works perfectly. The ‘head’ is somewhat bulbous, but does not detract from the final model. The arms evade the need for elbows and are fairly flat. However, the illusion is still achieved. A jet pack is carried on the back and seems logical in an arcade based universe. The true inclusion of the hologram blades becomes obvious when you construct the second model. The design for the jet is straightforward yet enjoyable. Although there is very little to point out on this build, I still thought it was worth the effort. It’s lovely to see TLG add extra instructions to rebuild a set. I find it noteworthy to point out the use of a video game controller as the jet’s steering mechanism.

Richie has his own vehicle in the form of a hoverboard. Though entirely simple, the idea is still conveyed. Finally, a Keytana is present and earns its own pedestal.

Overall

Kai’s Mech Jet is perfect for what it is, a 2 in 1 vehicle with bright coloring. The minifigures are fine, but not a reason to buy the set and there are very few rare parts. The half dozen stickers will likely deter some, but that is to be expected for a £19.99 or $19.99 set. However, for someone looking for a smaller sprightly set, Kai’s Mech Jet is certainly a sensible choice.

My 6yo son recently bought this set and I helped him build it. We first built the mech, and then the jet.

The Good

This is a decent set for the budget. It's relatively inexpensive, and it feels like you get above-average value for the money spent. Both minifigs are excellent. Kai comes with the typical smorgasbord of neon-green weapons and a dual-face. The Whack Rat is also pretty nifty, and I applaud the creative team for coming up with cool-looking baddies.

I really like the fact that this set is essentially two models in one. It means that the set's playability is versatile in ways most aren't. I think we're hitting a saturation point with Fire Mechs, but this one is far and away the easiest to get your hands on.

The models are also basically well-designed. The plane looks really cool, especially the forward-swept wings. The mech is the right level of poseable, with articulated joints at the shoulders, elbows, thighs and ankles. Both models boast modest firepower in the form of twin stud-launchers.

The Bad

So let's talk about the "transformation" from mech to jet and vice-versa. There isn't one. You have to almost completely deconstruct the set in order to build the other model. While I'm not expecting anything slick a la Transformers, it would be nice if there was at least a little fluidity in moving from one model to the other.

The jet uses far fewer pieces than the mech does. This means that when you've got the jet plane built, you've got a pile of unused parts just sitting there. If you're inclined to build random objects out of extra pieces, this can be a good thing. Otherwise, it can feel frustrating.

The jet and the mech themselves could use a little work, too. While I recognize that these are budget models, as it were, they feel rather flimsy. The mech was designed with no clear platform for Kai to stand on, so your best bet to keep him from falling out is to attach him via the back of his legs. It's also a bit of a bummer that Kai can't pilot the mech with his katanas strapped to his back. Similarly, the plane lacks a real cockpit; it more has the feel of Kai sitting atop a flying carpet. Neither the mech nor the plane have any designated controls, and neither have anything for Kai to really interact with (handles for steering the mech, cockpit controls, etc.). The nose of the plane is also a bit of a sore spot, as it is held on only by a pair of mechanical arms. It looks pretty cool the way it's angled downward, but there's really nothing substantial holding it in position.

Overall

In the end, the set is fine. Not spectacular, but definitely not poor by any means. The build is straightforward with mercifully few stickers. The finished models aren't very robust, but they make up for that in versatility. The minifigs are great, and the set definitely adheres to the videogame aesthetic that this season of Ninjago is all about.

My biggest gripe remains the clunky and disjointed transition between sets. I genuinely expected more of a "transformation" and less of a "take-apart-and-rebuild". That aside, however, this is a pretty good set overall.

First Look: Kai's Mech Jet is a pretty decent set. It looks nice, and I like the color scheme. It looks like maybe a brighter red than most of Kai's past vehicles, especially with the amount of white on it. Usually, Kai's color scheme is more red and black. I really like the white-on-red scheme. The stickers are consistent with Ninjago's Prime Empire (Season 12, or 2 depending on how you look at it. Technically, Ninjago is two different shows, "Masters of Spinjitzu" ending with Season 10 and just "Ninjago" beginning after that.) Personally, I'm not a huge fan of the show or too many of the sets, but this looks nice and very similar to 71709 Jay and Lloyd's Velocity Racers (they are from the same scene in the show). The parts here aren't too complex, but I like them. I could use a little more detail, but the stickers do justice and for 217 pieces it's not bad. At first, I didn't like the long green blades used for swords and wings, but I don't mind them anymore. I think they add something to the set -- both color and size. (Also, a note about the official pictures: the mech is holding one blade and the other two function as wings on the back. For some reason, seeing this, and I may be alone in this, I thought the blade was sticking out of the front of the mech. It is not; it is on the back and only looks like that.)

Kai's Mech Build: For a Ninjago mech... eh... I've seen better. I can't complain too much about this though -- it isn't bad, especially for its size. My first complaint: the tiny, spindly, puny legs. I didn't see this in the pictures (LEGO did a good job hiding it), but it is really kind of sad... I'm not sure what prompted the designer to pick such thin technic pieces to represent his legs, but this is what we got. Other than that, the legs are fine. I like the shield piece on the feet, but it has been used several times in recent mechs for that same purpose. The feet look good, and the thighs are nice and simple, with some sticker pieces on the outside. The thighs do, however, make the tiny legs look tinier. The body section feels good, it is nice and sturdy and functional. I would have liked to see the front close in the mech a little more; you can see the minifigure laying down essentially on the back of the mech (if the mech was laying down, Kai would be lying down on it). Other than that, the white enclosing section looks nice, especially with the sticker piece and the two white 1x2 ingot pieces. The arms are great and simple, following the same type of build as the rest of the mech. The fingers look awkward, but I like the gun hand and the swords on the forearms of each arm. The wings on the back are simple, and extend using a series of 1x2 hinge plates. This wing mechanism is very similar, but not the same, as the one on the back of the jet.

Kai's Jet Build: Kai's jet is smaller than the mech, not utilizing all the pieces in the set. The color scheme, of course, is very similar. There's not much to say about the jet... the pictures do justice to most of the design, and there's not much else hidden. My first complaint would be that the steering/driving console on a robot arm is connected to the front of the build, which moves. If you move the front of the jet up (I'm not sure why you would want to do this; it doesn't look great and has no purpose), the console's arm gets pushed against the stationary part of the jet where Kai sits. When you move the front back down, the console will move all the way forwards. It's not a big deal and can easily be fixed, but it is a design flaw. My other complaint would be about two pink pieces build into the bottom that you can see from the side or bottom that stick out of place. The wings are nice but have almost no range of motion. The third blade sticks way off the back, which looks a little awkward at first, but it adds a lot of length and is a great touch. The shape of the body looks really nice, with good shapes. I especially like the 1x2 grey log bricks and 1x2 slanted grille pieces, as well as the flaps on the back that can be angled up.

Playability: For playability, this set scores high. The mech and jet are both useful for play experiences and imagining scenarios from the show. Both have stud shooters, on the mech's left hand and on either side of the front of the jet. The sword in the mech's right hand has a decent range of motion and can be used for toy fighting. The enemy rat, Richie, has a small hoverboard that can be used to imagine he is flying around quickly while fighting Kai.

Minifigures: The minifigures included in this set are Digi Kai and Richie. (Disclaimer: as a Ninjago fan for 8 years now, having seen every episode and LEGO set, I am biased against Prime Empire because I simply do not like the season as much as previous seasons, and I do not like the modern, technological feel.) Compared to the other Digi ninja, Kai looks great. I appreciate his leg prints and how it lines up with the torso print. My favorite part is probably his white arm and transition into the left-hand side of the torso. The four (well, five if you count the one on the leg) blue circles are a nice touch, although blue circles are on all five Digi ninja. Digi Kai and Digi Jay look very similar, which I don't love, but they do both look good, so I can live with that. Kai's sword holder looks great, with slanted shoulder pads that are a nice touch. Kai's mask is good-looking, with his Digi symbol and white and red duel-molding. My only complaint about Kai would be his faces. I don't love the Digi face on any of the ninja, so I'm a little biased about that, but I also don't love his alternate face. He looks very scared and worried, so, if you dislike the Digi faces, your only option is a worried face. The video game controllers as sword handles are a very appropriate touch. The villain, Richie, also looks fine. I do not like the rat enemies or their outfits, so I really just do not like this outfit. His prints are detailed and his headpiece is very interesting. His weapon looks pretty amazing too. I think the Richie minifigure looks fine, but I do not really like him.

Price: The price-to-part ratio ($19.99 for 217 pieces) of this set looks pretty good. It's about normal, especially for a Ninjago set. Pieces are not very large, except for the green blades. For the amount of stuff here, I'm pretty happy, especially with the 2-in-1 feature of this set.

Recap: I wouldn't say this set is a favorite. It is small and simple. However, I do like this set -- it isn't bad. The main thing bringing this set down for me would be the whole Prime Empire theme, but it isn't bad. For $19.99, I think this is a well-made and good, playable set.