Reviews
MEGA BLOKS First Builders Big Building Bag JGK05, blue storage bag with blocks and simple builds
MEGA BLOKS First Builders Big Building Bag JGK05, tall tower built from the blocks
MEGA BLOKS First Builders Big Building Bag JGK05

Images: Mattel

Researched

MEGA BLOKS First Builders Big Building Bag JGK05

80 big, easy-grip MEGA BLOKS in a zip storage bag, made for toddlers from age 1.

$17.29 at Target · Price checked Oct 6

See it at Target

Prices at other stores may differ · Links go to the retailer

Our verdict

The First Builders Big Building Bag is MEGA BLOKS' starter set: 80 big blocks in 10 shapes and 9 colors that pack into a zip bag with a handle. It is rated for ages 1 and up. Mattel's own store lists the set but sends shoppers to retailers; Target sold the blue-bag version for $17.29 online when we checked, against Mattel's $19.99 list.

Target showed 4.8 out of 5 from 104 ratings. Parents of 1-year-olds say the blocks are easy to press together and pull apart, and several like the storage bag. The complaints are about quality and mix: one owner said builds fall apart, another found mostly single-stud blocks in uneven colors, and a third noticed pieces sometimes separate on their own.

It suits a first block set for a baby turning one, and the blocks are big enough for older siblings to join in. Skip it if your child is ready for DUPLO-size bricks and figures, or if you want blocks that hold firmly together for taller builds.

Key details

  • Ages 1+
  • 80 pieces
  • Building sets
  • MEGA BLOKS
  • Available

More info

  • Item number: JGK05 (blue bag)
  • Pieces: 80 blocks in 10 shapes and 9 colors
  • Material: Plastic
  • Storage: Zip bag with handle
  • Target TCIN: 92390993
  • Mattel list price: $19.99
  • Target price when checked: $17.29 online
Best for and who should skip it

Best for

  • Babies around their first birthday
  • Families who want blocks that pack into one bag
  • Siblings of different ages building together

Skip it if

  • You want sets with figures and a theme
  • You want builds that stay firmly together
What we like and what to keep in mind

What we like

  • Large blocks sized for small hands
  • Zip bag with handle for cleanup
  • Low price for 80 pieces

Keep in mind

  • Owners report many single-stud blocks and uneven colors
  • Some say builds come apart easily
  • Mattel's own store does not sell it directly
How we reviewed it

Researched, not hands-on tested. This review is based on the sources listed below. We have not tested this product ourselves. Check the current product listing and packaging before buying.

Based on the maker's specifications and public owner reviews, checked Oct 6, 2026.

MEGA BLOKS First Builders Big Building Bag JGK05, blue storage bag with blocks and simple builds

MEGA BLOKS First Builders Big Building Bag JGK05

Researched · Ages 1+

$17.29

Links go to the retailer

See it at Target

MEGA BLOKS First Builders Big Building Bag JGK05

$17.29 · Links go to the retailer

Check price

What owners say.

  • 2 positive
  • 1 mixed

Paraphrased from public owner reviews. Each one links to where it was posted.

Positive
A 1-year-old finds the blocks easy to put together and take apart, though pieces sometimes separate on their own when carried.
Target guest reviewApr 9, 2026
Mixed
Great for a 15-month-old who built for hours, but most pieces were single blocks in uneven colors.
Target guest reviewJun 4, 2026
Positive
Bought these years ago, and they still come out every time visitors with young kids stop by.
Target guest reviewDec 26, 2025

Sources.

What we read for this review, and when we last checked it.

  1. 01 Mattel. MEGA BLOKS First Builders Big Building Bag (80 Pieces), JGK05 shop.mattel.com · Checked Oct 6, 2026
  2. 02 Target. MEGA BLOKS First Builders Big Building Bag, Blue, 80pc target.com · Checked Oct 6, 2026
  3. 03 Target. Guest ratings and reviews target.com · Checked Oct 6, 2026

How it compares.

This toy next to the alternatives we suggest, using the maker’s details.

Detail MEGA BLOKS First Builders Big Building Bag JGK05, blue storage bag with blocks and simple builds This reviewMEGA BLOKS First Builders Big Building Bag JGK05 LEGO DUPLO Brick Box 10913, all 65 bricks, figures and car in a pile LEGO DUPLO Brick Box 10913 Fisher-Price Wooden Shape Stacker HXV05, wooden base with shapes stacked on four pegs Fisher-Price Wooden Shape Stacker HXV05
Price$17.29$29.99$7.99
Maker’s ageAges 1+Ages 1½+Ages 2+
CategoryBuilding setsBuilding setsWooden toys
Pieces806513
Good forA first block set for 1-year-oldsFirst bricks for toddlers from 18 monthsA small sorting toy for 2-year-olds
StockAvailableAvailableAvailable

Prices are the list prices we saw on the maker’s site and change often.

If this isn’t quite right.

LEGO DUPLO Brick Box 10913

LEGO DUPLO Brick Box 10913

DUPLO bricks with figures, from 18 months

See review
Fisher-Price Wooden Shape Stacker HXV05

Fisher-Price Wooden Shape Stacker HXV05

A small wooden sorter for age 2

See review

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