"tower of druaga sword & shield of uruk" is close i think.. there the characters also climbs a tower, mc is kinda lame at start but can be dependable too at times..
the op theme is good too.. "overlord" is yet another isekai title but it's great really (mc is badass)... "ragnarok the animation" old title but still pretty good(based on a game) "log horizon" another isekai good too (kuro shiroe!!).. try ".hack roots" weakish mc starts wanting power too(and he gets it, but....).. "tales of abyss" another title from a game, play the game then watch or vice-versa if your wondering if you need to watch/play the other tales series the answer is no so you can go ahead and watch it(song is great too that's a bonus).. "slime" a running title if you haven't watch it yet watch it now season 1 is almost over(hoping for a sequel)... "konosuba" great anime too and is funny as hell...
zero to hero, comedy, adventure, rpg, game, action, magic, isekai are some the tags/elements those titles have in common(i think)