I started playing Osu without a mouse on my laptop and I have been doing so since december when I first got this game. A lot of people say that its really difficult to play on a trackpad, but I think its easier than using a mouse. I can even play on hard beat maps up to 4 stars sometimes. Mostly I just play on normal though with hidden mods on. Are there any other players out there who prefer to play using a trackpad over a mouse?