Although this product is aimed at children and teaching them how engines work it was still fun for an early 20s guy and his dad to play with on a sunday afternoon.
There are some fiddly parts, especially the timing belt which took a little while to get right, but once it is done it is quite impressive to see it going like a real engine. I certainly learnt a lot about how engines work from this.
I would definitely recommend this to someone else, either as a gift or as something to play with themselves! I still love turning it on and watching it run and is a great product.