Thanks a lot for the review, and I'm glad you enjoyed it so much!
Just so you know, you should be able to open the save after completing the last level. If you avoid the crash (don't leave the last puzzle room, goto towerentrance instead!), you may even see the sky change to the nightly-purplish in relevant areas. ^^
I don't think I'll change graphics much for the immediate post-jam version - maybe some tweaks here and there or additional elements. I'd focus on deploying the softlock/crash fix, including some quality of life changes, making a few new levels, adding the missing sound effects and hopefully include the tracks for other levels of progression. I might make some kind of remastered version later on, with somewhat larger scope and hopefully refreshed graphics. We'll see...