Good price for cheap Chinese components.  Not ideal for a beginner.
590225
I'm not a beginner with electronics or micro-controllers.  I bought this kit to quickly and inexpensively grab some sensors for a project that I'm working on, and to add some parts to my parts bin.  I'll start by saying that the Arduino clone itself seems to be a perfectly workable unit.  It's available for ten bucks by itself on Amazon, and it's well worth the money.  The rest of the part in the kit, however, are a real mixed bag.  Several sensors (and the LCD display) came with seriously bent pins, and some of them (DHT11 and one of the potentiometers tested so far) are just plain dead.  I know how to implement and test these devices.  It isn't a mistake on my end.  They're dead.  Fortunately, those two components are worth less than $5, and other items seem to work, but I haven't had time to test them all.  Similarly, several of the male-to-male jumpers have literally fallen apart, something I've never before encountered with something as simple as a jumper wire.  The LCD display (once the pins were straightened) is one of the dimmest I've ever used, no matter how I adjust it.  For the price, assuming 75% of the components are functional, I still think this kit is a solid buy for a big pile of Chinese components, but I couldn't recommend it to a beginner, as the documentation (which comes on a CD) is very poor, and the shoddy parts could be very frustrating for someone without a spare on hand.
2866441
Instructions are in Chinese. Not great quality but expected for the price.
2139472
Cheap but good quality for someone just learning
1385191
Cheap poorly made, all the instructions and stuff are in Chinese or something. May still come in handy on occasion
2578371
Fun kit to assemble. Not for someone who needs explicit directions. Parts came labeled so just solder exactly as shown on the silkscreen on the PCB.

My kit came with all the needed wire in red, black and white.

Do not buy this kit if you know nothing about electronics.  There's no real reason to have explicit directions as they would tell you to just soldier the parts as shown on the PCB.

Troubleshooting would tell you to review the parts you installed to ensure they are pointing the correct direction and in the correct holes. Not much more they could tell you other than that.

I feel that most of the bad reviews are due to inexperience with electronics. Frustration caused by not knowing what the parts are or how they work. Missing parts is never a good thing, so I guess I was lucky that my kit came with everything.  If you do buy this kit and did not manage to get it working please understand that you have probably made a simple mistake.

I like the kit for the price.
3735317
Alright so here's a review from someone who bought this with their own money rather than just being given the board. It's alright for a starter board. I'd recommend saving yourself the time and cash and just getting a higher quality board not from amazon in the first place. I mean, you could spend $75 upfront and have to spend another $100 in upgrades as you get better or you could just spend that all upfront and just get a better board. Once again, not bad, but I'd look elsewhere for a better board if you're looking to continue getting better in the sport.
3818084
Kinda hard to mess up brass, but the steel punches are not properly heat treated, and will bend quite easily.  Can't expect much from cheap Chinese made stuff.  If I had to buy it again, I wouldn't.  Go spend the extra money to begin with, and you won't have to go buy a second, better set of punches later on.
1109741
One didn't work right out of the cheap box, all instructions are in Chinese, they come with some goofy button battery that good luck finding!
4215189
This is a nice bike for a beginner who's not going to be riding any steep terrain. The frame is sized for anyone 58 to 6 and has standard parts that can be easily found anywhere. Its got a 27.2mm seat post, 1 1/8 inch straight steer tube, 135mm rear axle and standard size disc brakes, which are all easy swap-outs.

My main problem with this setup is the freewheel gear, which has a horrible 14-28t gear selection. This needed to be replaced before I could ride it up any kind of hill. I also hate that the rear wheel is fitted with a threaded freewheel hub, making it impossible to upgrade to a cassette type gear cluster. Im going to have to replace the whole rear wheel, $100 down the drain.

I have a good quality 26 mountain bike, which Im swapping parts off of for this one, and besides the nightmarish freewheel; its made this bike into a halfway decent trail bike.

Out of the box, this bike is a total bummer on the trail. The fork has maybe 50mm of travel - bottoming out hard on small obsticles like roots and rocks. The brakes are way under-powered and any moderately steep hill needs to be taken very cautiously, as to not lose control. The tires are very heavy and made of a cheap  tar-like rubber making them hard to get up to speed even on pavement and make it ride sluggish and harsh over bumps.

I gave it two stars because the frame is good and it can be built-out into a good bike, but it'll cost you the price of a brand name bike, and still be inferior.

Been riding this setup for a year and love it! cant wait to upgrade the fork to a SR suntour XCM for some decent suspension travel. its nothing compared to my old lost Cannondale, but it still fun to ride even on hard trails.

My mods; Ive only put about 60$ into the bike. I did have a donor 26" bike to pull most of the parts off of.
Specialized stem, handlebar and headset, off my 1999' 26" Stump jumper frame; added a much improved cockpit.
Shimano LX 9 speed shifters, chain and 12-36 cassette; from the Specialized
Sinuote Disc Brakes; Avid BB5 clones: half the price too.
Schwinn High-Density Foam Mountain Saddle; best saddle Ive used, and a bargain
Shimano PD-M520 clipless peddles
Shimano Deore Disc rear hub; Rebuilt the rear wheel with it and double butted spokes.
Altus 44/34/24 crank; converted into a 34/24 2x9 by drilling out the rivets on the big ring, and modifying/cutting the front derailleur to fit 2 rings.
Geax Saguaro Tires; fast tread and light-weight and cheep, they really liven up this beast. Best investment so far.
4763793
When will we learn:  The Chinese make junk.  They make it with the cheapest, flimsiest materials available.  As long as the customer gets out the door before it fails, it's good enough for the Chinese.

Had this thing maybe a month when the usb socket came loose from the board, making this a piece of junk.

Smoov sellers, but apparently they never heard "fool me once, shame on you.  Fool me twice, shame on me."

I, however, have.
3289382
1. Quality Low; Can't believe some parts are Made In USA
2. Unless you are NOT PRO in technical & machine Don't Buy!
3. User Manual Lack of Pictures, specially on software install.
4. Price is Low, if you are a curious baby & Time Free, you can buy it to kill time.
5. Low Support, basically you will need to ask for help and no Official Forum.
6. Offsets are bad, about 4~6 parts have offset problems such as holes and joints offset in 2~4mm, you will need to fix yourself. DIY!
7. Parts may damaged during shipment... I got 2 parts damaged.
8. User Manual is not design for ThreeUp v2, You need to look this picture to check if you install it right.
2543181
For a beginner set, seems good.
Assembly is ridiculous.  I've never assembled drums before, so maybe that's just how it is.
Cymbals sound like junk, unless you're going for a clang clang sound. That's to be expected at this price point I suppose.
Everything else sounds good to me.
1337344
You get the components for the price, which is good. But the construction is cheap, the touchpad has large deadzones, the keyboard is flimsy and cramped (even with the size of this thing!), the headphone jack occasionally doesn't work, and you get loads and loads of Lenovo bloatware (some of which reinstalls itself if you try to remove it). My first order had a completely unresponsive touchpad and I had to return for a replacement. If you need the specs and want the price, go for it, but otherwise it's not a quality machine for the price. This is the last time I buy a consumer-line Lenovo.
1624337
If it comes from china, you're most likely gonna be upset. With this, you literally get what you pay for. Stupid cheap chinks.
2674547
This kit is cheap in quality and is probably worth about $15-$20 rather than $25. It does come with a fair amount of misc. parts.

My suggestion is to use a hot glue gun or apoxy on the bunsen burner stand because on its own it is too loose to stand up.
1912137
Not great.  They are cheap Chinese knockoffs, but for $10 you had to know that.  It functions, and does what it's supposed to.
If you have reasonable expectations, then for $10 they are a good deal.
2464208
Good for the beginner. If you are more of a professional though, then a more expensive and better quality kit may be needed. Excellent price though.