Under scenario 1 the locked levels are unlocked when lower levels are completed ?
Is there a reason to keep them locked ?
Do the lower unlocked levels introduce new game elements that are used in unlocked levels ?
Maybe theres a compromise somewhere in between
Lock levels that use “new” game elements until the lower levels that introduce those elements are completed then unlock the rest of the levels that might use that new game element (but not higher ones that have more new game elements)
There are new elements as the levels progress, but the major thing is difficulty
all puzzle boards are the same size (16x11) but the number of “targets” change, as to the number and types of “tools” and “obstacles”
The original (1999) version, unlocked levels in groups of 4 when you completed the previous 4 levels… but there were other releases that removed the locks completely.
One thing that is making me lean towards no locks, is that if you find a particular puzzle that can’t be figured out, you get frustrated, and there is no way to move on
Right, this is kind of what lead to the “level stars” type unlocks. You didn’t have to complete all the levels, but a good most of them to unlock the next bit.
A no lock puzzle is less challenging for true puzzle gamers. Experience puzzle people will find the solution for every puzzle you throw at them. That is my experience.