I have had success with the Simple Alarm Clock on F-Droid (not to be confused with the simple mobile tools apps). It has necessary basic features like custom alarms, increasing volume, and dismissing the alarm requires holding down "dismiss" so the chances of accidentally dismissing an alarm instead of snoozing it are much lower. The only time it seemingly failed me was after an overnight android update (samsung), where it didn't work until the phone was unlocked.