Thanks for giving the game a play! Yeah the game is a bit rough around the edges, we made it in ~8 days so, as you noticed, it could do with some adjustments and optimizations. You are able to unload your current inventory by right-clicking but that could maybe be made more obvious (and like you suggested the total inventory size just increased). An unlimited mode is a great idea - would be really fun!
Thanks again for playing! I'll add some screenshots in-case anyone else stumbles upon this game in the future :)