A few that come to mind for me are
- ASCII Sector - space roguelike that was released in the last 2000s
- Sonic Robo Blast 2 - free 3d sonic fangame, built using a Doom engine of all things…
- ClassiCube - free sandbox block-placing game that is similar to 2009/2010 Minecraft Classic
- Chronicles of Denzar - free browser-based RPG similar to dragon quest (previously PhantasyRPG.com) running since the early 2000’s
Tunic absolutely blew my mind. If you get the chance and love old school top down action with a twist (this game forces you to think) you might enjoy it.