1. SWAT Police (Arcade via MAME) 2/2
2. Gurumin: A Monstrous Adventure (PSP) 2/7
3. Barney's Hide & Seek Game (Genesis) 2/24
4. Metal Gear 2: Solid Snake (MSX via Vita Metal Gear Solid HD Collection) 3/8
5. TwinBee Da! (PSP) 3/10
6. Detana! TwinBee (PSP) 3/13
7. TwinBee Yahho! (PSP) 3/16
8. TwinBee (PSP) 3/19
9. Brain Lord (SNES) 4/27
10. Akumajou Special: Boku Dracula-kun (FC/NES) 5/8
11. BoxBoxBoy! (3DS) 5/16
12. Code:Realize ~Guardian of Rebirth~ (Vita) 6/26
13. Mario Kart: Super Circuit (GBA) 7/24
14. Dance Dance Revolution: Disney Dancing Museum (N64) 10/13
15. Fuga: Melodies of Steel (PC) 10/27
16. Phobos Dere .GB (GB) 11/6
17. Imagine Figure Skater (DS) 12/6
18. Gaia Seed: Project Seed Trap (PlayStation via Vita PSOne Classics) 12/30

I squeezed in one last beaten game too. I could've counted it earlier, as you get a credits roll even after clearing the first four stages in Practice mode, and getting credits is usually my bar for considering a game beaten, but that would just feel like cheating here. So I'm counting the day I actually earned an ending by completing all seven stages.