The last couple games I enjoyed playing and beating were Undertale and Portal 2.
Portal 2 was great with lots of puzzles and challenges. Lots of table-turning events and action but no true violence as your only "gun" is a device that shoots portals that you can warp through to reach other areas. There's no blood and language isn't too bad either with only a few mild swears. The game is certainly challenging and increases in difficulty as you pass through test chambers and facilities.
Undertale was a great game with a unique and enjoyable design. The rich storyline was easily graspable and the gameplay itself was very fun. You have to fight fictional monsters to receive XP and LV or you can spare your enemies by doing friendly actions rather than hitting them. Fights are bloodless with the enemy only turning into pixelated dust when killed. When not fighting monsters in the Underground, you can walk around doing various tasks and talking with the NPCs.
Thanks for reading!