PHYNEDI 555Pcs 1:1 Simulation Mechanical Military Shooting Toy Blaster Bricks Model Set, Small Particle Assembly Educational Model Building Toy

Instructions are terrible. They are just pictures and there were a couple instances where the instructions didn't say to add a piece but we were somehow just supposed to guess it was needed. No idea how the rubber bands work so our doesn't fire, but it looks ok. In one picture it showed a loose rubber band and then two pages up the same rubber band was crossed, with no instruction to cross it. It was just in the picture where we were attaching a different piece unrelated to the bands. Good luck getting the rubber bands right with these instructions and that's the only thing working the trigger mechanism. The stickers aren't 100% accurate with the picture but that's not a big deal. You definitely need better instructions to get this to actually fire.

Pretty good but the park where I have to make the back of the gun is in a bit hard and the string doesn't help that much

The set up for the mechanism was really complicated. My son built the body and barrel of the gun but had difficulty with the gears. I tried to help and I was so confused and we never even managed to put it all together.