In Frizzle Fraz, you have to collect keys to unlock the doors of each level.
The difference is that there's a bit more movement and address here, and the scenes are expandable, not static. You will have to avoid or remove the various enemies that may present themselves and recover the small frizzles.
This does not mean that you will not have to think and be clever to achieve your goals, but it is one criterion among others...
The levels are rich in terms of novelty, possibilities, decor.