Since there are some guides here, i'd like to include some basics i have found to very very important on my own. That being said, it means perhaps others mention them, but i think these should stand out to someone just starting the game without knowing anything about it. After all someone who likes the game and have issues with it, will research it properly eventually.

This is a 20 turn game. Every ability has a cooldown (CD). This means that using abilities efficiently makes a huge difference.

♣There are single target abilities and there are Area of Effect Abilities (AoE) and there are also Area Denial abilities.

♠The efficient way for an AoE ability is to have at least 2 targets (preferably even more). A good example in this category is Lockwood's "LIGHT ‘EM UP", Blackburn's "PROTEUS GRENADE", Nix's "VORTEX ROUND". You want those abilities to be used with 2 or more targets.

♦Area Denial abilities usually don't do direct dmg. Damage in the turn they are used that is, but only in the next turn. These include, Nix's "
OVERWATCH DRONE", Lockwood's "TRAPWIRE", Zuki's "THE BIG ONE" and so on. It is important to decide when to use what. There's a huge difference between doing direct dmg and leaving it for the next turn, especially when you are close to finish off a target. Zuki's "STICKY BOMB" is a very good AoE ability when the enemies are at full health and you have 2-4 target line of sight for example. Very poor choice when you choose to use it on enemies with 40-60 HP.

♥Dashes. Dashes should be used to get you out of trouble! This is critical! You have 1 dash ability and one Catalyst. Use your limited amount of dashes carefully and wisely.

Abilities have mods and this means some abilities may change they way they act, keep that in mind.

I am a PvE player by 99,9%, i only play PvP if i hit "Play" without switching to "vs Bots", because by default the game is on PvP. Well, it is a PvP game after all, yet i enjoy the the PvE experience. My experience thus far is that most players (in PvE) are very inefficient when using abilities/skills/dashes. Even an average gamer like me should be able to pick up on the game mechanics after awhile. I hope this helps speed up the process.