I played this a lot back in the day on the Amiga 500. Funny thing is, my skills in this game seems to be worse now, than when i was a kid. Anyone else experiencing this? :P

When i was a kid, i reached the "Circus"/3rd world and now i can hardly reach level 3 in the "Castle"/2nd world. I never completed the game though.

It is not just you, I think it's the DOS Box and slightly iffy controls. tbh, this version is a slight disappointment.. I found it easier to play in a window (Alt + Enter). I played and completed the Amiga version but this version seems more difficult..
I'm struggling to get off the first world, level 3.. Even in Easy, even with 7 lives :(