You forgot a key event; custom movement doesn't use event checkable stepping loops unless you add this.
+ System: Start of layout (or whenever the sprite is created)
-> Sprite: Set moving style to Linear with 1 Pixels per step
edit: just tried it in your cap and it appears to lag with 1 pixel per step. I set it to 3 and it works fine.
[quote:pvw7v5rz]and if someone knows how this could work just the same without the detector sprite, please let me know
What does the detector have to do with stepping? stepping just makes it so that you can check for fast moving collisions without skipping through objects. Or was that just an additional question?