I'll be honest, I don't understand what I'm supposed to do. I got the pushing part and that I can somehow reshape the blocks, but then I'm stuck.

Nice submission.
I wish there was more levels to it but I understand that a week is short.
If you plan on improving your game, here’s few things you should consider:

• add a little tutorial (or levels that introduce only one game mechanic at a time)
• replace the “hold to grab” mechanic by a toggle “grabbing/not grabbing”. Like other comments said, moving around with a finger holding another key is not ideal.
• add an outline on the crates/boxes so they don’t end up lost in the level

I definitely see the vision here. The visuals though, at least for me, make it pretty hard to tell where stuff is, especially when you're walking on top of those funky animated tiles. You just sort of get lost in the pixels. The numpad control scheme was also pretty awkward, having to hold down 7 while also moving with 8 4 5 and 6 was a little clunky. Still though, I like what you were going for.

Web version didnt work for me but the native one worked fine. It needs variety, and at least a tutorial since it took me a while to figure out where the actual places to put the boxes on were. Terrain seemed decorative only, would be cool if the terrain was blocked off and sectioned in a way that forces a specific sequence to get the rocks to the end, like sokoban.

Nice game.
I wish the web version were working so more people would check the game and rate it.
But these things happen during GameJams. 

Good game, I would like to see its evolution