I've been doing a bit of work on level sequencing. On the left, the level order as it stood in playtest build 1.21 (last week). On the right, the changes I've made over the weekend.
As you can see, most of these changes involve shuffling around the same selection of levels, but there has also been one level scrapped and another added. We're trying to keep the first half of the game quite lean, and focus on introducing, teaching and reinforcing a succession of new mechanics. LaserShield was a good candidate to be cut – I'm not happy with the aesthetics of the level, and its major purpose at that point in the sequence was to separate other levels. It may be put somewhere in the 30s, but for now it's back in the Polish folder.
I've moved SoleRoute, SwapPrimer, DualRoute, and Edu_BlockSwap up a couple of spots. These levels consist of two related pairs, interleaved to keep it interesting for the player, and to avoid the appearance of trying to deliberately orchestrate the player's appearance at all.
In playtesting, we've found many players had trouble with Adv_BlockSwap. This is a challenging level, one which poses the player an unfamiliar problem: they must die at least four times to complete the puzzle, but after the fourth death the block they need decays away and disappears. The solution is in starting with the newest (green) block, but getting access to it requires using an older block to push it clear of the hazard. To better prepare the player for this, I made Edu_BlockSwap last week to teach the technique, but even that level is (despite the 'edu' category) a fairly difficult puzzle. The problem is, that while Edu_BlockSwap is as simple as I can make the concept, the time delay between the critical error and it causing problems makes it difficult for players to recognise what went wrong. Though it doesn't use the 'blockswap' technique, I created SwapPrimer to use a similar concept, in an attempt to better prime the player for Edu_BlockSwap.
This is followed by DoubleSwap, which I've edited to be far easier (it should now probably be downgraded to a 'med' rating), restricting the areas of smooth floor to direct the player. This level draws a lot of attention to the blockswap technique, and placing it immediately after Edu_BlockSwap should help to immediately reinforce the concept. This should better prepare the player for the very difficult challenge of Adv_BlockSwap. The player needs a mental break between these high-intensity levels however: LaserPlug, a fairly simple filler level. It's not too complex and doesn't contain any new concepts, so I think it's a good choice to separate the two challenging swap levels and give the player a bit of a 'breather' before tackling BlockSwap.
Adv_BlockSwap is the capstone to the laser section, and is still followed by the repulsion beam introduction and education levels, but after that I've swapped the position of the next two levels. I had previously thought to have Stack first, but placing StairGateAtlantis first has the advantage of a similar layout to the educational level before it (Edu_Repulsion_1_Buildup), which cues the player up a little better for the puzzle.