You should definitely have a lot of wrench-use, like routing cables to the correct place and such. This could then activate redstone signals giving access to a chest, which has a piece of flint. There'd be another chest containing a wooden bowl. You could then Mortar some of your ingots and make bronze dust, then placed in a furnace. the furnace is powered by a Furnace Heater, powered by a solar panel or 2 which you must find hidden in the level. After you get the ingot, you put it in a chest where it is immediately taken to be the final component in an Automatic Crafting Table. Once the item is done, it sends a redstone signal to open the exit door of the level and giving you the prize. This could for example be the Forestry Grafter if the next level is related to Tree Breeding. Or it could simply activate the restone signal and give you an IC2 jetpack required for a platforming level. Alternately, you could give them a fuel jetpack that is not required but to be used for their own leisure if they conserve their fuel cans found as a bonus in each level. So it wouldn't be required, but it'd give more of a feeling of accomplishment and a reward for their efforts. Of course this bonus would make some platforming levels much easier, so you'd limit fuel cans accordingly.