The game should work great in the browser whether downloaded or not! Download the ZIP and put both files in the same folder, then double-click on 'littleghost.html'. It should open like a normal webpage.

The binaries just need to be downloaded and unzipped on the correct kind of computer - they should work from the unzipped folder with no extra messing. I'm just using the built-in PICO-8 binary export, but please let me know if something is weird with them. It is a new enough feature.

If you have PICO-8 and want to check out the game's code/etc. or just play it in the 'real thing', download either littleghost.p8 or littleghost.p8.png to your pico-8/carts directory, then load from within the game with 'load littleghost'.