Tank wars! Or whatever it was called. I will find a picture.
Something like this
Any Canadian's remember that old Halloween YTV flash game where you broke into this old guy's house to get something. It was a basic adventure game but there was a timer of sorts and every time it ran out the guy would appear and you were supposed to have concealed yourself. If you didn't conceal yourself in the right place he would find you and then...kill you? Or did he just throw you out?
An embarrassing a lot of amount of Adventure Quest...
Also, I don't remember it looking so bad, damn, I really didn't care about graphics as a kid.
Planetarion - man the hours I sunk into that. Think it's still going too. I played it 2002-2003 I think
My handle on EpicDuel (another Artix game) and elsewhere around the Internet Cosmos is Zookfoodle, the name of an NPC from DragonfableI played AdventureQuest, MechQuest, DragonFable, and AQWorlds A LOT when I was younger. Absolutely addicted to them. I think my battleon name was BlackFlameWarrior...what a fucking edgelord name lmao.
Besides that, I also played Trackmill and random stuff on Newgrounds.
This probably doesn't count since it was more of early to mid 2000s, but I have very fond memories of playing Slime Soccer and Slime Volleyball in computer lab back in middle school. I remember we used to do stupid little world cup tournaments in Slime Soccer all the time.
I think one I used to play was called InkLink? Some drawing game where you'd play against other people.