>>14305369
- You Have to Win the game (A simple but fun platformer, free on Steam)
- Banana Nababa (a simple but hard 2D boss rush game)
- G-Type (mix between R-Type and Gradius)
- Gigadeep (pretty rough Megaman X clone)
- Castlevania Fighter (Boss rush game made on the Mugen engine. It's got lots of content)
- AM2R ("Another Metroid 2 Remake", in the style of Zero Mission. Go play it fag)
- Eternal Daughter (a decent Metroid like game)
- Gianna's Return (Classic hard as fuck platforming)
- Liero (Worms on steroids)
- Momodora 1 & 2 (platformers inspired by Cave Story)
- Celestial Mechanica (nice platformer. Free on Playism) and Infinos (simple shmup, also free on playism)
- Noitu Love
- Ausable
- Barkley Shut up and Jam Gaiden
- Rescue the Beagles
- Castlevania The Lecarde Chronicles 1&2
>Fan Games with Custom Levels
- Super Mario Bros X (custom levels with lots of content, 4 player coop)
- DOOM WADS, you can spend your whole life just playing them
- Mari0 (Mario with the portal gun, it has lots of options and a very good level editor)
- OpenBOR games (Beats of Rage, Marvel Ultimate Alliance, Contra Locked N' Loaded, Night Slashers, Knights and Dragons, among many more)
- Streets of Rage Remake (the best Beat em up ever made)
- Zelda Classic (Open source port of the first zelda game. Comes with an editor and many custom zelda games have been made with it)
- A shit ton of RPG Maker games, some have been mentioned in this thread (Yume Nikki, Space Funeral, Off, and a long etc.)
I just wish Elysis and Super Castlevania 3 were still in development.
>>14305714
Having decent, free and modifiable tools is good for everybody. A propietary software company has to actually compete make a better product than the free alternative in order to make their products worth a buy.