I test my own some years ago its 135. Its not too bad, but no too good. its above avarage.
I have some special skills. Thanks my asberger syndrome. Extremely good visual memorize skills. Just not about lemmings only. I can remember every capital citys and flags in whole world, but my math is bad one. My School went pretty okay overall. Not very good, not too bad, somewhere avarage ranges. My geography was always best possible, but math and english was worse. My Socials skills is probably worst ever in world.
Lemmings requires just most your visual skills. When you have look level overall and look little things everywhere. Most my skills is my experience. But i am extremely good visual skills player myself.
About lemmings games. I think everybody can beat orginal lemmings games if your IQ is around 100. But beat some very hard custom levels make this game really hard. Lemmings is like Shack.
I´ll keep little bit break make my own NeoLemmix custom levels rightnow and back to play Plus 1 Psycho mode again. I am got 100 hours practice about game and thats make most levels really easy. I´ll think my own pack is harder one. We always overlooked somethings. I am have to fix my own levels many times. Its not easy make hard levels, but interesting levels.
Todays i spend 12 hours make per each single level. Probably my masterwork solution, that was worth it. I did easy and hard version with this level. Also easy version seems tough one, but hard version is really fun.
I think i can make my pack done end of the this year, but have to check out it many times, so its will be public somewhere next year. Its seems i am sometimes overlooked something. Its take a lot time make one single level. Usually 4 hours, sometimes 12 hours.
Have to say Namida making extrmely good job Lemming plus levels. All licensed games was simply too easy for me. Make without pausing give me some fun. Namida Plus 1 are giving me good challenge. Few Psycho leves are remain, but i am completed those quite fast when i start make my own levels. I learn that mechanism. Thats will be fun progress.