Very loosely based on the concept of the H.G. Wells novel.

First it seems like half the movie is people epileptically dancing. The teenagers in the mud. Then people in the club. People at the village party. And the giants show themselves. That's more than a third of the movie time. Though the duck dancing art was fun.

Once you remove that the best parts are Ron Howard's (as a child mad scientist). And the story goes ok, up till the giants appearance. Afterwards, not so much.

The giant teenager want to take control of the city, but there's nothing happening except they get some KFC delivered.
The final parts and the plan to get rid of them are pretty bad. First it's absolutely stupid. Then Fred basically does not move and just watch them trying to capture him without doing anything. And the whole David/Goliath thing is even worse.

The "giants" effects are mostly them moving slowly which is pretty annoying.

Very convenient: when they grow, they end up naked, but when they shrink back, their clothes shrink too !