Controls and platforming are good - character has a good weight to them - collision could do with a little bit of work, for example, pushing boxes into objects, and clipping slightly into the side of platforms. Some of the platforms were difficult in places to differentiate from the back.
Had an issue on the second level where i managed to push the box down the hole to block the laser, but got stuck down there? couldn't see a way to open the menu to restart so had to restart the application.
Second playthrough - didn't realise there was a double jump! managed to make it to the end.
The sickness mechanic adds a good natural timer to the levels which can be extended by the pickups - maybe have a risk/reward system for exploration? might be able to find items to lower the meter and get more out of the level, but at the risk of getting too sick.
Enjoyable experience, congrats!