Fillomino. Divide the grid into regions. Each region is composed of cells, each cell containing a number equal to the size of the region. No two orthogonally adjacent regions may have equal sizes. Medium
UPDATE: Fixed ambiguity around middle right.
Fun and not so obvious. Probably. At least my intended opening wasn’t so obvious. EDIT: Apparently not really. Although there are a few unusual deductions, nothing too hard. But still fun for me at least, as progress are made in circles. If you know what I mean.
This is why I don’t really enjoy making large puzzles, much like Para. Too many tricks that clutter the fun tricks, although I can put in a bunch of small tricks. The latter can also be lost if I accidentally made an easier way to do stuffs. Well, let’s see how people respond…
Puzzle 21, which is in 12 hours, is a Fillomino. With a variation.