Scaling an image on an external image editor (like Ps) does produce better results however (in my opinion).
maybe im doing soemthing wrong but i cant share this opinion
the ikarus sprite is scaled in construct2 (added in large size and then just dragged to the size i wanted) while the boarder on top and bottom are tiledbackgrounds which where scaled with photoshop and then cleaned by hand of the "artifacts" added by the ps scaling
Another solution is to create 2 tilemaps, one for each resolution and load the appropriate one depending on which device you are playing on.
that sounds complicated but maybe that is my solution, will try that