http://www.mangago.me/read-manga/tensei_shitara_slime_datta_ken/
http://www.mangago.me/read-manga/sozai_saishuka_no_isekai_ryokouki/
http://www.mangago.me/read-manga/when_a_stupid_fps_player_falls_to_another_world/
(it's not really level up but maybe you will be interest in them)
Maybe you will like those too :
http://www.mangago.me/read-manga/berserk_of_gluttony/
http://www.mangago.me/read-manga/tate_no_yuusha_no_nariagari/
http://www.mangago.me/read-manga/konjiki_no_word_master_yuusha_yonin_ni_makikomareta_unique_cheat/
http://www.mangago.me/read-manga/ore_to_kawazu_san_no_isekai_hourouki/
http://www.mangago.me/read-manga/ex_strongest_swordsman_long_for_magic_in_different_world/
http://www.mangago.me/read-manga/isekai_yururi_kikou_kosodateshinagara_boukensha_shimasu/
http://www.mangago.me/read-manga/legend_takano_masaharu/
http://www.mangago.me/read-manga/tensei_kenja_no_isekai_raifu_daini_no_shokugyo_wo_ete_sekai_saikyou_ni_narimashita/
http://www.mangago.me/read-manga/maou_gakuin_no_futekigousha/
http://www.mangago.me/read-manga/hachinan_tte_sore_wa_nai_deshou/
http://www.mangago.me/read-manga/isekai_yakkyoku/
http://www.mangago.me/read-manga/murabito_desu_ga_nani_ka/
http://www.mangago.me/read-manga/tondemo_skill_de_isekai_hourou_meshi/
http://www.mangago.me/read-manga/yankee_wa_isekai_de_seirei_ni_aisaremasu/
http://www.mangago.me/read-manga/world_teacher_other_world_style_education_agent/nbt/888e9c3e08193718/Ch1/
http://www.mangago.me/read-manga/peerless_dad/
Anyone know any manga like "solo leveling" or "A Returner's Magic Should Be Special" (about a guy becoming stronger) ლ(´ڡ`ლ)