Dang! I love side-scrolling games but can't remember the settings you mentioned. The thing that comes to my mind are Rick Dangerous 2 and Dangeorus Dave, but both these do not fulfill your criteria.

Ermm... remember the weapons he used in that game? How the enemies look like - humans or creatures or both?

Other game in a castle like setting is Magic Pockets by Bitmap Brothers. But he throws various items as weapons - candies, sticks, toys etc.

EDIT :

1. Is it a VGA, EGA or CGA game?
2. Weapons used - projectile or melee (guns or swords)
3. Does the Tech/Nerd wear glasses?
4. Does the whole gameplay takes place in the past alone? Is it a medieval setting?

Blackthorne?

http://www.mobygames.com/game/blackthorne

Sounds cool...almost like King's Quest meets Flashback?

1. Is it a VGA, EGA or CGA game? 2. Weapons used - projectile or melee (guns or swords) 3. Does the Tech/Nerd wear glasses? 4 […]
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1. Is it a VGA, EGA or CGA game?
2. Weapons used - projectile or melee (guns or swords)
3. Does the Tech/Nerd wear glasses?
4. Does the whole gameplay takes place in the past alone? Is it a medieval setting?

Hmm...
1: it was definitly VGA,
2: i dont remember using weapons at all or enemies for that matter 😢 (of course, i can be wrong) , the only sure danger was some gaps you had to jump over. It was a very slow paced game, like a mix between an adventure game with side-scroller perspective, when you enter a door sometimes it transported you another part of the level (sidescroller) and sometimes it showed a Picture of the room your in and you could search it for items.
3: possibly 😖
4: not sure, i dont remember ever completing the game, but i am sure at least the first level was on a dark castle

Blackthorne?

Thanks, but nope 🙁 although it had Blackthorne's Dark Atmosphere, but.... inside a castle 😜

Sounds like Time Runners to me.

It looks like the game is here in this video between :06 and :08 and :10 to :13.Maybe the person who uploaded the video knows what it is.

http://www.youtube.com/watch?v=jCNnYXh1TvU

Sounds like Time Runners to me.

Yes! after looking at this Screenshot of Time Runners i am 100% its this one 😊

Thanks everyone! expecially you Sir Vogons 😁 whew! been looking for that game for like months 😅

Sounds cool...almost like King's Quest meets Flashback?

i did searched for Flashback and it seems like a good game, also thanks 😁

now the question is.... where i am gonna find this game 😳

Glad to be of service.

searching for dos time runners turned up a few good results.