Can this game be run on PC? I am trying to play the game on PC using ym PS4 controller plugged in and is it slower?

The PC version is actually a different game called "M&M's: The Lost Formulas". https://www.speedrun.com/mms_the_lost_formulas

If you meant using an emulator, your mileage may vary on the emulator used, but any Xinput controller should work out of the box on windows, and any DirectInput controller should work given the right drivers. The DS4 is a popular controller on PC, so you should be fine in that regard.

Will an emulator run slower? Yes, it will run slower than a PS2 with Fast Disc Speed. This game has a lot of lag and so even the PS2 model makes a difference. I don't think PS2 emulators are mature enough to be on par with consoles. It'll either run slower, or faster (in which case it shouldn't be allowed, anyone can make their own version of an emulator that runs faster than console).

Yes you are correct, I tried running this game on emulator and its slower than PS2. I have also compare some splits to the current WR and its different although the first 3 level is auto scroller. Guess, no point in me attempting the game since I do not have this game on my PS2 though for me to compete with WR.

As a word of advice, if you prefer being able to compete for WR in general, very few PS1 games will be viable for you as they're almost all ran on PS2 w/ FDS. And often (not always, it depends on the game), a model 90k will be optimal.

You can however use the hot swap trick to play any PS1 game (burned, different region, etc.) on a PS2 slim. Easier done on a 90k since 70-75k have an additional lid sensor inside. (or you can use a swap magic disc). Burned discs will still read slightly slower than factory pressed ones, but have given me a better experience than emulator. And it's not flash/usb loading.