the idea behind gish 2 was to have an open world zelda style that you would traverse side scrolling, there would be different zones and a dungeon in each zone that would turn into a level set like the 1st game with a big boss at the end.
so it was a bit metriodvaina over world with traditional dungeon level sets.
gish would gain new abilities and be more blob like, he could split into pieces and you could control 2 gishes at once.