K.O.L.M. was and is my favourite flash game of all time. Most flash games (except Edmus of course) I'll simply play for 30 mins and forget about it, but not only did I play K.O.L.M. - the day I discovered it, I went home and played the whole thing from start to finish. Then on my next day off, I played through it a second time. Now, a sequel has been released - you must play this game.
K.O.L.M. is easily as polished as any you'll find on Xbox LIVE or PSN, and it's as well designed to boot. Essentially a Metroid-inspired platformer (K.O.L.M. stands for Kind Of Like Metroid) blends a sublime art design, puzzles, and incredible level design with a sombre narrative. It's an absolute class above.
I've just gotten started with K.O.L.M. 2, but so far so good.
If you haven't played the original, do so now. If you have, get excited for the sequel!
K.O.L.M. 2 [Armor Games]