My 1 yr old neice, who also shared in his party since their b-days are only a day apart, also rode on this roller coaster with only a little supervision. There were 2, 3, 4, 6 8 yrs olds at the party each of them rode enjoyed it.
He is a little advanced for his age walked at 8 months, so although a little hesitant, I thought this would be a great outdoor toy that he could play on now with our assistance grow into as well. I bought this Up Down Roller Coaster after reading so many reviews of what a great toy this was for their children. I was looking for an outdoor toy for my son's 1st birthday. In fact, my 8 year old cousin was the one who put it together in seconds before my husband had the chance to put the box away. The peices just slide together, no tools needed.
I even took a turn it is super durable. It really was the hit of the party. Don't be hesitant to buy this. It's a little big, but stores easily since the peices come apart.