You’ll also find it easier to meet your playthrough requirement target if you play certain games. If everybody played the lowest risk games (like even bets on roulette) to meet their playthrough targets then casinos would lose heavily, so the concept of game Weights is always used to prevent any problems.
A game weighting is the percentage of any wager that counts towards meeting redemption. 100% of all virtually all slots wagers always count, with lesser percentages of wagers on other games like roulette,
no deposit blackjack and videopoker contributing.
As always, it’s always worth checking exactly how a no deposit bonus works before accepting one – but as long as you bear in mind the concepts explained above then you’re unlikely to come unstuck.