It's fine as a casual distraction, but I can't recommend it because there's a barely-hidden "gold ceiling" to the gameplay -- meaning you can't progress with any sort of reasonable speed past a certain point in the gameplay without spending a significant amount of real-world money.

Star Trek Timelines seemingly attempts to hide just how much you're spending through various fictional in-game currencies. Be sure to convert what you're being asked to spend to real-world money before you agree.

The character card packs are similarly disingenuous. You're regularly offered an array of three-to-five character cards for a fee, and told that you will one of the character cards if you buy in.

However, if you check the small "i" icon in the upper right of the offer -- it lists the win chances which they are presumably required to provide by law -- you will discover that the odds of winning any of the rare or unusual character cards are significantly lower (e.g. 1%) than the other, more common cards you've seen before and may already own.

You may wonder how this is not considered gambling, but the law in most jurisdictions only classifies games as gambling if you can win *nothing* when you play. So long as you walk away with something -- no matter how trivial -- it's not classed as gambling under the law.

So, Star Trek Timelines is not bad as a casual, low stakes entertainment for fans of Star Trek, but if you have visions of "collecting all of the things" and progressing to the highest heights of the game, best keep your eye on your money, and always be aware of how much you're being asked to spend or to risk.

My opinions anyway. Yours may vary.

A good game that you can dip in and out of, whether it's on your mobile or on your PC.
It does help if you can pay for items, but you can play the game for free. I've only spent £4.99 on this game and have already played 72 hours (achieved 9 out of the 10 achievements so far), so for me it represents good value for money.