Or you can use LiteTween addon.It would be much easier, quicker and cleaner.
But unfortunately Scirra is reluctant to adapt it to the new runtime, even though it is extremely useful.
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Indeed that's why I was reluctant to say use rexrainbow MoveTo as it seems impossible to add on Construct 3.
I'm on the train to London doing this on mobile and a few beers in so may be a bit rough. But it works.
T in the lerp is linear so start stop with constant speed but as it is using lerp you can drop in a smoother line formula for t to make it ease in and out.
drive.google.com/open
arrows or hold/double tap move left right