Exploring other worlds with LEGO Creator 3-in-1 31115 Space Mining Mech [Review]

If you’re here, chances are you’re a big fan of the LEGO brand, so you already know that it’s the toy of endless possibilities. Even on more expensive sets, you’re most likely always going to get a good bang for your buck. And in terms of creative potential, Creator sets are some of the best at encouraging it, particularly 3-in-1’s which provide a great combination of inspiration and versatile parts. The latest addition to the line is finally here, and we’re eager to see if this space-themed kit is out of this world! Come along as we explore what LEGO Creator 3-in-1 31115 Space Mining Mech has to offer. The set will be available March 1st, and will retail for  US $24.99 | CAN $34.99 | UK £24.99.

The LEGO Group provided The Brothers Brick with an early copy of this set for review. Providing TBB with products for review guarantees neither coverage nor positive reviews.


The box and contents

The front of the box immediately draws your attention to the imposing robot mech with its giant bladed arm and little alien friend. The other builds don’t look nearly as cool on the front, but the back shows a bit of potential.

This set includes 4 small polybags and 3 half-page instruction booklets. The main book has a QR code so the builder can use digital instructions if they choose.


The main model

We’ll start with the namesake build for this set. This robot mech is slightly similar to 31090 Underwater Robot, although it’s safe to say it’s a bit more complicated and interesting. (Which is expected at this higher price point.) I’d say it’s equal to the sum of its parts (in a good way), so we’ll break it down as such. The body itself is sturdy as heck, which is typical of compact LEGO robots. There are also joints and moving parts everywhere, which is awesome!

Moving on to the arms of the mech, the spinning blade is composed of 8 pearl dark grey tooth elements attached to two octagonal 2×2 with bar frames of the same color via 16 1×1 clips. In other words, it’s sturdy. It basically an irresistible fidget spinner on an arm. On the opposite side, the best thing about the fingered hand is the use of 1×1 modified rounded plates with bar handle. What’s cool is that this element provides great flexibility compared to the old square plates. This makes it look more like a hand, and in terms of grip, it has its limits, but it still creates loads of playability. The model also has you building a cute little alien with scary-looking teeth that fits fairly well in the mech’s palm. It too is jointed so you can open its mouth.

The legs are composed of rigid knees and extra-large feet. Although the inability to move the knees is a bummer, the rest is quite posable, and the large base that the feet provide allows for great stability. And even though they can’t move, the design of the knees actually looks kind of cool.

One of the best parts of the mech is the jetpack. Not only does it do a good job of using the truncated cone and dome elements for jets, but it also has a pocket for packing whatever it is they’re mining.

There’s not a lot to the cockpit other than some knobs. Of course, if you’re a robot operating a robot, who needs control panels? That said, the shape of the opening smooth and satisfying. The clear half-dome hatch fits quite perfectly, and a minifigure would sit comfortably.

While it would’ve been really cool to get a space minifigure to man the robot, it’s tradition for 3-in-1 sets of this size/price point to not include them. Additionally, it appears that robots and aliens (or alien robots) are the dominant creatures on this planet. Instead of a fig, a nondescript AI is in charge. Presumably, the neon trans-yellow plate represents a good mood, and if you flip it over, pink represents an angry one.

Build two

This time the robot is operated by another, more loveable, bot. Unfortunately you have to make-believe that his little arms can reach the controls. Even though Mixel joints are used, they don’t allow for movement in the right direction.

Speaking of limited range of movement, the pod in the back also barely opens. It seems that this is intentional, but I’m not sure why. You can remove the 1×2 trans-green brick “space crystals” from the pack, but there doesn’t seem to be a reason to make it complicated. While it makes sense for the bottom to not be able to drop from the weight of the contents, I would argue that it would be much more fun if the top opened enough to store a wide variety of things.

The feet are both the best and worst parts of this model. On one hand, they look kind of cool, especially compared to the rest of the build. But on the other hand, they are not at all stable. If the toes were rigid instead of jointed, they might support the rest of the foot better. Unfortunately, the whole leg assembly is not designed with center-of-gravity in mind. Even though the joints are all posable, playability is reduced because it almost refuses to stand upright unless in one specific position.

Perhaps it’s like reading runes, but there must be something in the leftover parts that would make this model better. Better looking and better at standing. (You’ll see the full model in the next section) At least we have a few interesting bits for making other cool things, like the new butter (bright light yellow) colored 1×2 brackets.

Build three

We kick the second alternate off with another small alien robot thingy. Although the eyes have been around for a little while now, it’s worth commenting on how fun they are. The shape allows for all kinds of expressions, without needing eyebrows. That said, even though the feet employ the same parts in the big robot hand, creating the ability to make new poses, it’s rather boring. It’s a shame, considering how many fun parts are left over at the end of this build.

One thing that’s neat about this rover is the base. The instructions have you constructing the body of the vehicle first, in two halves. The space in the middle where they’re supposed to connect is weak, making the whole thing fragile and a little frustrating to keep together as you continue to add bits. But when you finally add the base, it’s super solid. What they should have done was build the bottom first, or at least early on. In regards to the base itself, it’s not only sturdy but fairly posable. While it can’t move in the middle, it can still achieve several positions. Most importantly, it’s inspiring. And by that I mean the shape and posability stir up lots of ideas for other robots or animals. Personally, I plan to make a gorilla with this technique.

The completed model feels a little reminiscent of 31107 Space Rover Explorer from last year. Although, as an alternate model instead of the headliner, this one is smaller and much less detailed. Like its cousin, this model sports a pair of front claws for exploratory grabbing and a truck bed style storage area for hauling space stuff.

As previously mentioned, this time we’re left with a solid handful of unused parts. Which, again, allows for the builder to get creative on their own. That said, some of the pieces really would’ve been nice to see in the official build to add more character or detail.


The completed models

The size and style of LEGO robots and mechs run the gamut, but I’d have to say that this is one of the best. Also, of all the Creator 3-in-1 sets, this particular model is one of my very favorites. It’s just super fun to build and play with, isn’t going to fall apart too easily, and has a few neat techniques. Pop a minifigure in the cockpit and its all-day fun for a kiddo.

Now some bad news for the first alternate… Generally speaking, I always have something nice to say about the sets I review, and any time I have a criticism, it’s usually mild and I have ten good things that follow it up. This time, I just can’t do it. This alternate build is awful. While the main robot is one of my favorite Creator 3-in-1 builds ever, this has to be my least. Its resemblance to an AT-ST walker from Star Wars is only fleeting, and it feels amateur and uninteresting. Period.

The second alternate model is cute and classic Creator fare. It’s not overly exciting, but it has some redeeming qualities compared to the other alternate build. The base isn’t complicated, but it’s satisfyingly strong and provides a lot more playability. There are three identical little 1×2 neon trans-green bricks with greebly bits to be built with this model. Who knows what they’re supposed to be, but we can assume they’re impure bits of whatever these alien robot guys are trying to mine.


Conclusions and recommendations

If you (or special kiddos in your life) love robots and mechs, the headliner for the set might be perfect. It’s a fun build with a few neat techniques and I enjoyed playing with it. The walker-style bot might be cool for some, but I found it completely lackluster. And the little rover was mildly redeeming, but not enough to encourage you to take apart the mech. The variety of parts is fair, other than it’s nice to have lots of joint elements. Therefore, I wouldn’t call this an exceptional parts pack, especially because the price per piece is higher than one would hope for such a set. (Generally, $0.10 per piece is worth it and this set is $0.15 per piece.)

(WHOOPS! The lemurs were playing with our office calculators. The Price Per Part on this is actually under 8 cents, which is a much nicer ratio. Watch the comments for an updated evaluation from the reviewer!)

So, the verdict? This set is for people who love the main model. Otherwise, wait for it to go on sale or spend your hard-earned cash on another awesome kit. Perhaps consider the new Creator 3-in-1 31116 Safari Wildlife Tree House that I reviewed a couple of days ago.


Creator 3-in-1 31115 Space Mining Mech will be available March 1st from the LEGO Shop Online for  US $24.99 | CAN $34.99 | UK £24.99. It will also available via third-party sellers on Amazon and eBay.

The LEGO Group provided The Brothers Brick with an early copy of this set for review. Providing TBB with products for review guarantees neither coverage nor positive reviews.


5 comments on “Exploring other worlds with LEGO Creator 3-in-1 31115 Space Mining Mech [Review]

  1. Jimmy

    “Instead of a fig, a nondescript AI is in charge. Presumably, the neon trans-yellow plate represents a good mood, and if you flip it over, pink represents an angry one.”

    As the parent of a 4y old girl, I can say with 100% confidence that the pink is a girl AI. Or at least that is how my kiddo would interpret it.

    We’ve tried to raise her with gender-neutral toys, clothes, etc. and to show her strong female characters and role models (vs. princess in distress that must be rescued by a strong man). Despite this, she is totally all-in with pink/purple/sparkle/unicorn/rainbow/princess/fairy life. It’s not a bad thing (I mean I like sparkles too!), that’s her choice and I’m not mad, it’s just amazing how much of that is either ingrained or picked up through secondary sources like schoolmates or wherever.

  2. Håkan

    I found learning to read runes was fairly easy, but I’d still have trouble coming up with any alternative builds that’d pass Lego’s quality control…

  3. Bre Burns Post author

    Thanks for the comments about the PPP guys! You’re correct, I completely misspoke. I must of mistakenly typed the wrong thing into my calculator real quick, and didn’t realize that the output was obviously incorrect.

    As for an update to my conclusion: the correct PPP would make me consider purchasing this a bit more, but still not so much for the “set” aspect, personally. It’s decent as a gift for a kiddo and much better as a parts pack, but the PPP doesn’t reverse my slightly negative opinions about the design. Sadly, that alternate build is no better at $0.08/piece than $0.15.

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