These blocks are pretty neat! We already have lots of the Mega Blocks brand so I wanted to try these as an alternative. I have a 4 and 1 year old and they're perfect for both ages. My 4 year old can easily build with them, although she does say they're 'harder to take apart' than the slippery (hard plastic) Mega Blocks, and my 1 year old tries to put them together, but mostly chews them lol. They have the same bright colors and shape as the others, so I was hopeful they would fit together (making our set larger), but they don't QUITE fit together. But it's ok to have 2 sets. They are not exactly silicone as I thought they would be (like a silicone ice cube tray), but more like very stiff, silicone coated material. They are matte finish, but are still hard plastic (not flexible), so they don't clatter as much then dropped. Overall, great set to build with - I got the 36 piece and it has enough variety to make different houses and forts.